Hindawi Publishing CorporationConference Papers in Materials ScienceVolume 2013 Article ID 878014 7 pageshttpdxdoiorg1011552013878014

Conference PaperMicrostructural Characterization of Natural FibersEtlingera elatior Costus comosus and Heliconia bihai

Claacuteudia I T Navarro Sidnei Paciornik and Joseacute R M drsquoAlmeida

Materials Engineering Department Pontifıcia Universidade Catolica do Rio de Janeiro Rua Marques de Sao Vicente225 Gavea 22451-900 Rio de Janeiro RJ Brazil

Correspondence should be addressed to Jose R M drsquoAlmeida dalmeidapuc-riobr

Received 1 August 2013 Accepted 8 September 2013

Academic Editors R Fangueiro and H Hong

This Conference Paper is based on a presentation given by Jose R M drsquoAlmeida at ldquoInternational Conference on Natural FibersmdashSustainable Materials for Advanced Applications 2013rdquo held from 9 June 2013 to 11 June 2013 in Guimaraes Portugal

Copyright copy 2013 Claudia I T Navarro et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

This work describes the structural and morphological characteristics of fibers obtained from the stem of three ornamental plantsnamely Etlingera elatior Costus comosus and Heliconia bihai The stems of these plants are long and nowadays do not have anyuse being disregarded The results obtained showed that the three fibers have a crystalline index of around 58 and are thermallystable to approximately 230∘C 240∘C and 255∘C for E elatior C comosus andH bihai respectively The fibers present an averagehumidity amount of less than 9 and the thermal degradation peak for the cellulose component varies from 358∘C for E elatiorto 379∘C for C comosus The morphological analysis showed that the fibers present a large variability of the shape of their cross-sections which are preferentially elongated These morphological characteristics were used to estimate the error made when oneconsiders the fibers having a circular cross-section

1 Introduction

From very ancient times natural fibers were used in severalapplications such as sacks but starting at the middle of theXX century they began to be largely replaced by syntheticfibers These man-made fibers present several advantagessuch as uniformity of properties including the mechanicalones However the increasingly concern of the society witha sustainable development promoted a come back to ligno-cellulosic materials and today natural fibers are replacingsynthetic ones such as glass fibers for example at the auto-motive industry [1]

In fact lignocellulosic fibers are a very attractive optionboth economically and ecologically since they are not toxichave normally a low price have low density and are less abra-sive to the molds and processing equipment Besides theyconsume less energy to be produced and are biodegradableand neutral with respect to CO

2emission [2]

Although one can cite several advantages as above theuse of lignocellulosic fibers also presents several disadvan-tages One can highlight the hydrophilic behavior of thesefibers which can hinder the fiber to matrix adhesion onceseveral common polymeric matrices are hydrophobic incharacter Also the hydrophilic nature of the lignocellulosicfibers can contribute to fast humidity absorption leading to aconsequent loss of dimensional stability of the manufacturedpart

Another disadvantage of using lignocellulosic fibers is theintrinsic variability of their properties due to several causesencompassing variables ranging from the age of the plant andits harvesting time to soil fertility and weather variationsBesides due to the fact that they have a natural origin thecross-section shape and size can largely vary from fiber tofiber and also along the length of a single fiber This is animportant aspect since it is usual to determine a typicalfiber ldquodiameterrdquo and to assume that the fibers have a circular

2 Conference Papers in Materials Science

Figure 1 Procedure used to obtain sharp cross-section Aftersoaking the fibers in water the use of a doctor blade enables a cutwithout deformation artifacts due to the cutting procedure

cross-section when one wants to characterize the cross-sec-tion of a lignocellulosic fiber [3]This approach can be a crudeone and can have influence on the evaluation of the mechani-cal properties of the fibers since it can generate cross-sectionareas far apart from the real ones [4ndash6]

Besides the more common lignocellulosic fibers largelystudied and in many instances already used in severalcommercial products such as jute (Corchorus capsularis)sisal (Agave sisalana) and flax (Linum usitatissimum) severalother less common fibers also have a great potential tobe used as reinforcement in polymer matrix compositesLess common fibers here meaning fibers that are not yetlargely exploited due to being restrict to a certain ecosystemandor region or simply because they are only obtained asa by-product of other harvests Several examples can becited here such as fibers extracted from palms (piassava(Attalea funifera) [7] or Borassus flabellifer [8]) or fromother plants (eg from Urtica dioica [9]) Another source oflignocellulosic fibers is the vast market of ornamental plantsand flowers In Brazil this is a growingmarket with a financialturnover amounting around 22 billion dollars per year Asmany ornamental plants have stalks as long as 15m and sinceonly their top part is commercialized the leftover residueshave a great potential to be processed to obtain long or shortfibers that can be used as reinforcement in polymer matrixcomposites

In this work the structural and morphological charac-teristics of fibers obtained from three ornamental plants(Etlingera elatior Costus comosus and Heliconia bihai) arestudiedThemorphological aspects of the fibers were studiedby both scanning electron microscopy and digital imageanalysis and the structural characteristics were accessed byX-rays diffraction and thermogravimetric analysis Specialemphasis was given to the digital image analysis techniqueto characterize the true cross-section shape and area of thesefibers and to discuss the results obtainedwith those calculatedconsidering the fibers as with a circular and uniform cross-section

2 Methods and Materials

The fibers used in this work came from a farm located at RioBonito county RJ State Brazil These fibers were obtainedfrom the leftover stems of the following ornamental plants

Figure 2 Manual outline of the fiberrsquos perimeter Example for a Ccomosus fiber

Fmax

Fmin

Figure 3 Definition of the size parameters of an object

Etlingera elatior Costus comosus and Heliconia bihai Thecommon names of these plants are respectively torch gingerred tower ginger and heliconia The fibers were obtainedusing a manual molasses mill This simple device removesvery efficiently the sap of the residues has a very low energeticconsume and produces fibers as long as the processedresidue Fibers averaging about 40mm were obtained inthis work This equipment was already successfully used toprocess fibers from the leftover residue of pejibaye palms [10]

These fiberswere then suitably processed to the analysis tobe performedTheywere powdered to the thermogravimetricand X-rays diffraction analysis The X-rays analysis wasperformed from 2120579 = 5∘ to 2120579 = 80∘ with increments of002∘ using Cu-120581120572 radiation (120582 = 15406 A)The analysis was

performed using an equipment setup of 40 kV and 30mAThe crystalline index CI of the fibers was calculated usingthe following relationship [11]

CI = [(119868002minus 119868am)

119868002

] times 100 (1)

where 119868002

is the intensity of (002) plane reflection and 119868am isthe intensity of the amorphous material at 2120579 = 18∘

The thermogravimetric analysis was performed from28∘C e 750∘C using a heating rate of 10∘Cmin N

2atmo-

sphere and a gas flow of 20mLminThemass of the samplesranged from 867mg to 1179mg

To be analyzed at the scanning electron microscope(SEM) fibers 25mm long were used These fibers were first

Conference Papers in Materials Science 3

1000

800

600

400

200

0

Lin

(cou

nts)

0 10 20 30 40 50 60 70 80 90 1002120579 (scale)

16∘

2236∘

3455∘

(a)

1575∘

222∘

347∘

1000

800

600

400

200

0

Lin

(cou

nts)

0 10 20 30 40 50 60 70 80 90 1002120579 (scale)

(b)

1485∘

22∘

3475∘

1000

800

600

400

200

0

Lin

(cou

nts)

0 10 20 30 40 50 60 70 80 90 1002120579 (scale)

(c)

Figure 4 X-rays diffractogram of the fibers (a) E elatior (b) C comosus and (c) H bihai

immersed in water for around 6 hours and were then cutusing a doctor blade as depicted in Figure 1 This simpleprocedure guarantees a smooth cross-section without defor-mation artifacts usually observed when dry fibers are cutThe cut fibers were dried at 70∘C plusmn 5∘C until constant weightand were subsequently mounted vertically at a specimenholder to have their cross-section analyzed at the SEM Atthis step the fibers were individually mounted at the sideof the cylindrical SEM specimen holder with a double facetape carefully aligning them with the vertical axis of thespecimenholderThis guarantees that the fibersrsquo cross-sectionrests transversally to the microscope axis since the specimenholder is perfectly aligned with this axis

Although this was a very time-consuming step it provedto be feasible and the cross-section of the vast majority of thefibers was at a horizontal plane perpendicular to the micro-scope vertical axis Therefore measurements errors at the fi-bers cross-sections geometrical parameters were minimized

100

80

60

40

20

Wei

ght l

oss (

)

0 100 200 300 400 500 600 700 800Temperature (∘C)

0

minus2

minus4

minus6

minus8

minus10

Derivative of w

eight loss (m

in)

Figure 5 Thermogravimetric behavior of the H bihai fiber Thesame overall behaviorwas also observed forE elatior andC comosusfibers

4 Conference Papers in Materials Science

1816141210

86420

Num

ber o

f fibe

rs

02 03 04 05 06 07 08 09 10Aspect ratio

(a)

1816141210

86420

Num

ber o

f fibe

rs

02 03 04 05 06 07 08 09 10Aspect ratio

(b)

1816141210

86420

Num

ber o

f fibe

rs

02 03 04 05 06 07 08 09 10Aspect ratio

(c)

Figure 6 Aspect ratio histograms from (a) E elatior (b) C comosus and (c) H bihai fibers

(a) (b)

Figure 7 Examples of the large fibersrsquo cross-section variability found for C comosus

SEM images were captured using a beam electron voltageof 20 kV on gold sputtered samples and at the secondaryelectrons imaging mode

Digital image analysis was used to characterize the fibercross-sections However due to the very irregular shape ofthe fibers and to the fact that their images were collectedseparatelymdashone by onemdashit was not possible to use a com-pletely automated analysis process as described in a previouswork [6] Here the first step of the digital image analysis was amanual outline of the fiberrsquos perimeter as shown in Figure 2After this border was delineated all the following analyses ofthe fibers could be fully automated Fifty fibers from E elatiorand C comosus and 40 from H bihai were analyzed

The parameters used to the morphometric analysis of thefibers were the true fiber area (119860

119879) obtained just by counting

the image pixels contained inside the outlined perimeterthe maximum and minimum calipers (119865max) and (119865min)corresponding respectively to the longest and to the shortestprojection of the fiber Figure 3 [12] and the aspect ratio (AR)defined as the ratio between (119865max) and (119865min) considered asa good measure of the cross-section elongation

The measurement of both maximum and minimumcalipers has also the objective to estimate a circular area ofthe cross-sections since it is a common place to assumethat the fibers have a circular cross-section when traditionalmeasurements methods such as when micrometers or othercalipers are used Since the image analysis methodology

permits the direct measurement of the true area of the cross-section it is also possible to estimate the error commitedwhen the maximum or the minimum calipers are usedas representative measures of an ldquoapparent fiber diameterrdquoThese errors can be calculated using the following equations[6]

119864119865max=

100381610038161003816100381610038161003816100381610038161003816

119860119879minus 119860119865max

119860119879

100381610038161003816100381610038161003816100381610038161003816

times 100

119864119865min=

100381610038161003816100381610038161003816100381610038161003816

119860119879minus 119860119865min

119860119879

100381610038161003816100381610038161003816100381610038161003816

times 100

(2)

where 119860119865max

and 119860119865min

are the circular areas calculatedrespectively using 119865max or 119865min as the fiber diameters

3 Results and Discussion

Figure 4 shows the results of the X-rays analysis The spectraof the three fibers are as expected similar and show thepresence of the three characteristic peaks of native cellulosenamely [13 14] (i) the peak with the highest intensity at 222∘corresponds to the diffraction of the (002) plane (ii) a broadpeak between 14∘ and 16∘ corresponds to the diffraction of

Conference Papers in Materials Science 5

times105

5

4

3

2

1

0

Are

a (120583

m2)

AreaTrue area Area from feret max Area from feret min

lowast

lowast

lowast

lowastlowastlowast

(120583m2)

AFmax AFmin

(a)

Are

a (120583

m2)

lowast

lowast

lowast

lowastlowastlowast

times106

30

25

20

15

10

05

00Area

True area Area from feret max Area from feret min(120583m2)

AFmax AFmin

(b)

40

Are

a (120583

m2)

lowast

lowast

lowast

lowastlowastlowast

times106

35

30

25

20

15

10

05

00Area

True area Area from feret max Area from feret min(120583m2)

AFmax AFmin

(c)

Figure 8 Comparison between the true fiber area directly measured by image analysis and the areas calculated assuming circular cross-sections (a) E elatior (b) C comosus and (c) H bihai fibers

both (101) and (101) planes and (iii) the peak around 34∘corresponds to the (040) plane

The crystalline index of the fibers evaluated from (1)showed no significant statistical difference between the fibersThe values obtained were 585 578 and 585 for respec-tively E elatior C comosus and H bihai fibers These valuesare similar to values reported for several other lignocellulosicfibers [15]

Figure 5 shows the thermogravimetric behavior observedfor the H bihai fiber and it is also representative of thebehavior of the other two fibers At the temperature rangebetween around 30∘C and 90∘C there is a mass loss attributedto loss of humidityThe valuesmeasured for the three types offibers are listed in Table 1 and agree with the values reportedfor several other lignocellulosic fibers [7 16 17]

Table 1 Humidity loss and peak temperature of the cellulosedecomposition of E elatior C comosus and H bihai fibers

Fiber Humidity loss Peak temperature ∘CE elatior 89 358C comosus 78 379H bihai 88 370

Theonset of the thermal degradation of the fibers definedas the temperature where a mass loss of 1 occurs at the pla-teau following the humiditymass loss began at around 230∘Cfor E elatior 240∘C for C comosus and 255∘C for H bihaiThe subsequent mass loss is mainly attributed to the thermal

6 Conference Papers in Materials Science

Table 2 Statistical comparison between the true area and the circular areas calculated using the maximum and minimum caliper valuesStudentrsquos 119905-test between the average values

Area calculated using the maximum caliper Area calculated using the minimum caliperE elatior Yes (119875 = 18119864 minus 7) Yes (119875 = 25119864 minus 6)C comosus Yes (119875 = 94119864 minus 7) Yes (119875 = 42119864 minus 5)H bihai Yes (119875 = 71119864 minus 7) Yes (119875 = 25119864 minus 5)95 confidence interval Yes means a statistically significant difference

decomposition of hemicellulose as well as to the rupture ofglycoside link of the cellulose molecule and the rupture of 120572and 120573 aryl-alkyl-ether linkages originated from the thermaldegradation reactions of lignin [18 19]

The last thermal degradation step is associated to thedegradation of cellulose and the value where the peaktemperature of the cellulose thermal degradation occurredmdashobtained from the DTG curvemdashis also listed in Table 1The values obtained closely agree with the values reportedfor the thermal degradation of cellulose from other severallignocellulosic fibers [20]

Figure 6 shows the histograms of the aspect ratio of thefibers obtained from digital image analysis results Thesehistograms show that the fibersrsquo cross-section has a largevariety of forms since AR presents a large range of values Infact one can observe that forE elatior values ranging from02to 09 with an average of 060 and a standard deviation (SD)of 015 were obtained C comosus fibers showed a similartrend with AR values ranging from 03 to 09 with an averageof 063 and a SD of 014 H bihai fibers also showed valuesfrom 03 to 09 The average value here was of 055 with a SDof 013 Figure 7 shows some cross-sections where one canclearly observe the very different shape of the fibers Besidesthe histograms of Figure 6 show that the cross-section of thefibers is preferentially elongated since AR values are smallerthan 1 AR values approaching unity mean a more equiaxialfiberrsquo cross-section

In Figure 8 the graphs compare the true area measuredby image analysis with the circular areas calculated from theminimum and maximum calipers The Studentrsquos 119905-test wasapplied assuming a 95 confidence interval and has indicatedthat there exists a significant difference between the truearea and the calculated circular areas for the three analyzedfibers These results are listed in Table 2 and show that thecircular area calculated both from the maximum or fromthe minimum caliper is statistically different from the truemeasured cross-section area

The errors between the circular areas inferred using thecalipers as ldquodiametersrdquo and the true areawere calculated using(2) Therefore for each specimen of each fiber two errorswere calculated namely 119864

119865maxand 119864

119865min when the maximum

caliper and the minimum caliper were used respectivelyFor the population of each fiber maximum minimum andaverage values of each error were then calculated Thesevalues are listed in Table 3 where one can see that errors aslarge as 300 can be generated assuming the fibers as circularobjects

Table 3 Values of 119864119865max

and 119864119865min

for the three fibers species

E elatior C comosus H bihai

119864119865max

()Maximum 273 267 337Minimum 28 37 48Average 108 116 142

119864119865min

()Maximum 69 59 61Minimum 2 5 2Average 31 23 31

4 Conclusions

The thermal and structural characteristics of fibers obtainedfrom the stems of three ornamental plants were analyzedin this work These stems are nowadays considered justas waste at the economic branch represented by the flowerand ornamental plants market However the obtained resultsindicate that these fibers have thermal stability and crystallineindex similar to the values found for other lignocellulosicfibers already used as reinforcement in polymer matrix com-posites Therefore from their structural characteristics thesefibers are possible candidates to be used as reinforcement incomposites for example at interior door panels

The fibersrsquo cross-section morphology was also analyzedand the results indicate that the values obtained by digitalimage analysis can be strongly different from the onesobtained when the fibersrsquo cross-sections are considered ascircular Determination of the aspect ratio showed that thefibers have in fact an elongated shape meaning that thecircular cross-section hypothesis can be a crude approx-imation The image analysis approach was shown to bean important tool since its use significantly increases theaccuracy of the measurements made on each fiber andalso enhanced the statistical significance of the morpho-metric parameters measured since the number of fibersanalyzed can be increased without a considerable increaseon the analysis time requested This is a key point aboutdigital image analysis since using usual techniques involvestime-consuming steps and the number of parameters mea-sured andor the number of objects analyzed is usually low

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Conference Papers in Materials Science 7

Acknowledgment

The authors acknowledge the financial support from theBrazilian Funding Agency CNPq

References

[1] J Holbery and D Houston ldquoNatural-fiber-reinforced polymercomposites in automotive applicationsrdquo JOM vol 58 no 11 pp80ndash86 2006

[2] A K Mohanty M Misra and L T Drzal ldquoSustainable bio-composites from renewable resources opportunities and chal-lenges in the greenmaterials worldrdquo Journal of Polymers and theEnvironment vol 10 no 1-2 pp 19ndash26 2002

[3] C Bergfjord and B Holst ldquoA procedure for identifying textilebast fibres using microscopy flax nettleramie hemp and juterdquoUltramicroscopy vol 110 no 9 pp 1192ndash1197 2010

[4] J L Thomason J Carruthers J Kelly and G Johnson ldquoFibrecross-section determination and variability in sisal and flax andits effects on fibre performance characterisationrdquo CompositesScience and Technology vol 71 no 7 pp 1008ndash1015 2011

[5] X W Xu and K Jayaraman ldquoAn image-processing system forthe measurement of the dimensions of natural fibre cross-sectionrdquo International Journal of Computer Applications inTechnology vol 34 no 2 p 115 2009

[6] J R M drsquoAlmeida M H P Mauricio and S PaciornikldquoEvaluation of the cross-section of lignocellulosic fibers usingdigital microscopy and image analysisrdquo Journal of CompositeMaterials vol 46 no 24 pp 3057ndash3065 2012

[7] J R M drsquoAlmeida R C M P Aquino and S N MonteiroldquoTensile mechanical properties morphological aspects andchemical characterization of piassava (Attalea funifera) fibersrdquoComposites A vol 37 no 9 pp 1473ndash1479 2006

[8] K O Reddy B R Guduri and A V Rajulu ldquoStructuralcharacterization and tensile properties of Borassus fruit fibersrdquoJournal of Applied Polymer Science vol 114 no 1 pp 603ndash6112009

[9] S M Mortazavi and M K Moghadam ldquoIntroduction of anew vegetable fiber for textile applicationrdquo Journal of AppliedPolymer Science vol 113 no 5 pp 3307ndash3312 2009

[10] B C Temer and J R M drsquoAlmeida ldquoCharacterization of thetensile behavior of Pejibaye (Bactris gasipaes) fibersrdquo Polymersfrom Renewable Resources vol 3 no 2 p 33 2012

[11] V Tserki N E Zafeiropoulos F Simon and C PanayiotouldquoA study of the effect of acetylation and propionylation surfacetreatments on natural fibresrdquo Composites A vol 36 no 8 pp1110ndash1118 2005

[12] S Paciornik and M H P Maurıcio ldquoDigital imagingrdquo in ASMHandbook Metallography and Microstructures G F V VoortEd pp 368ndash402 ASM International Materials Park OhioUSA 2004

[13] M Z Rong M Q Zhang Y Liu G C Yang and H M ZengldquoThe effect of fiber treatment on the mechanical properties ofunidirectional sisal-reinforced epoxy compositesrdquo CompositesScience and Technology vol 61 no 10 pp 1437ndash1447 2001

[14] D M R Georget P Cairns A C Smith and K W WaldronldquoCrystallinity of lyophilised carrot cell wall componentsrdquo Inter-national Journal of Biological Macromolecules vol 26 no 5 pp325ndash331 1999

[15] J F Revola A Dietrich and D A I Goring ldquoEffect of mercer-ization on the crystallite size and crystallinity index in cellulose

from different sourcesrdquo Canadian Journal of Chemistry vol 65no 8 pp 1724ndash1725 1987

[16] J R M drsquoAlmeida A L F S drsquoAlmeida and L H de CarvalholdquoMechanical morphological and structural characteristics ofcaroa (Neoglaziovia variegata) fibresrdquo Polymers and PolymerComposites vol 16 no 9 pp 589ndash595 2008

[17] A Bismarck A K Mohanty I Aranberri-Askargorta et alldquoSurface characterization of natural fibers surface propertiesand thewater up-take behavior ofmodified sisal and coir fibersrdquoGreen Chemistry vol 3 no 2 pp 100ndash107 2001

[18] B Wielage T Lampke G Marx K Nestler and D StarkeldquoThermogravimetric and differential scanning calorimetricanalysis of natural fibres and polypropylenerdquo ThermochimicaActa vol 337 no 1-2 pp 169ndash177 1999

[19] K C M Nair S Thomas and G Groeninckx ldquoThermaland dynamic mechanical analysis of polystyrene compositesreinforced with short sisal fibresrdquo Composites Science andTechnology vol 61 no 16 pp 2519ndash2529 2001

[20] A L F S drsquoAlmeida V Calado D W Barreto and J RM drsquoAlmeida ldquoEffect of surface treatments on the dynamicmechanical behavior of piassava fiber-polyestermatrix compos-itesrdquo Journal of Thermal Analysis and Calorimetry vol 103 no1 pp 179ndash184 2011

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2 Conference Papers in Materials Science

Figure 1 Procedure used to obtain sharp cross-section Aftersoaking the fibers in water the use of a doctor blade enables a cutwithout deformation artifacts due to the cutting procedure

cross-section when one wants to characterize the cross-sec-tion of a lignocellulosic fiber [3]This approach can be a crudeone and can have influence on the evaluation of the mechani-cal properties of the fibers since it can generate cross-sectionareas far apart from the real ones [4ndash6]

Besides the more common lignocellulosic fibers largelystudied and in many instances already used in severalcommercial products such as jute (Corchorus capsularis)sisal (Agave sisalana) and flax (Linum usitatissimum) severalother less common fibers also have a great potential tobe used as reinforcement in polymer matrix compositesLess common fibers here meaning fibers that are not yetlargely exploited due to being restrict to a certain ecosystemandor region or simply because they are only obtained asa by-product of other harvests Several examples can becited here such as fibers extracted from palms (piassava(Attalea funifera) [7] or Borassus flabellifer [8]) or fromother plants (eg from Urtica dioica [9]) Another source oflignocellulosic fibers is the vast market of ornamental plantsand flowers In Brazil this is a growingmarket with a financialturnover amounting around 22 billion dollars per year Asmany ornamental plants have stalks as long as 15m and sinceonly their top part is commercialized the leftover residueshave a great potential to be processed to obtain long or shortfibers that can be used as reinforcement in polymer matrixcomposites

In this work the structural and morphological charac-teristics of fibers obtained from three ornamental plants(Etlingera elatior Costus comosus and Heliconia bihai) arestudiedThemorphological aspects of the fibers were studiedby both scanning electron microscopy and digital imageanalysis and the structural characteristics were accessed byX-rays diffraction and thermogravimetric analysis Specialemphasis was given to the digital image analysis techniqueto characterize the true cross-section shape and area of thesefibers and to discuss the results obtainedwith those calculatedconsidering the fibers as with a circular and uniform cross-section

2 Methods and Materials

The fibers used in this work came from a farm located at RioBonito county RJ State Brazil These fibers were obtainedfrom the leftover stems of the following ornamental plants

Figure 2 Manual outline of the fiberrsquos perimeter Example for a Ccomosus fiber

Fmax

Fmin

Figure 3 Definition of the size parameters of an object

Etlingera elatior Costus comosus and Heliconia bihai Thecommon names of these plants are respectively torch gingerred tower ginger and heliconia The fibers were obtainedusing a manual molasses mill This simple device removesvery efficiently the sap of the residues has a very low energeticconsume and produces fibers as long as the processedresidue Fibers averaging about 40mm were obtained inthis work This equipment was already successfully used toprocess fibers from the leftover residue of pejibaye palms [10]

These fiberswere then suitably processed to the analysis tobe performedTheywere powdered to the thermogravimetricand X-rays diffraction analysis The X-rays analysis wasperformed from 2120579 = 5∘ to 2120579 = 80∘ with increments of002∘ using Cu-120581120572 radiation (120582 = 15406 A)The analysis was

performed using an equipment setup of 40 kV and 30mAThe crystalline index CI of the fibers was calculated usingthe following relationship [11]

CI = [(119868002minus 119868am)

119868002

] times 100 (1)

where 119868002

is the intensity of (002) plane reflection and 119868am isthe intensity of the amorphous material at 2120579 = 18∘

The thermogravimetric analysis was performed from28∘C e 750∘C using a heating rate of 10∘Cmin N

2atmo-

sphere and a gas flow of 20mLminThemass of the samplesranged from 867mg to 1179mg

To be analyzed at the scanning electron microscope(SEM) fibers 25mm long were used These fibers were first

Conference Papers in Materials Science 3

1000

800

600

400

200

0

Lin

(cou

nts)

0 10 20 30 40 50 60 70 80 90 1002120579 (scale)

16∘

2236∘

3455∘

(a)

1575∘

222∘

347∘

1000

800

600

400

200

0

Lin

(cou

nts)

0 10 20 30 40 50 60 70 80 90 1002120579 (scale)

(b)

1485∘

22∘

3475∘

1000

800

600

400

200

0

Lin

(cou

nts)

0 10 20 30 40 50 60 70 80 90 1002120579 (scale)

(c)

Figure 4 X-rays diffractogram of the fibers (a) E elatior (b) C comosus and (c) H bihai

immersed in water for around 6 hours and were then cutusing a doctor blade as depicted in Figure 1 This simpleprocedure guarantees a smooth cross-section without defor-mation artifacts usually observed when dry fibers are cutThe cut fibers were dried at 70∘C plusmn 5∘C until constant weightand were subsequently mounted vertically at a specimenholder to have their cross-section analyzed at the SEM Atthis step the fibers were individually mounted at the sideof the cylindrical SEM specimen holder with a double facetape carefully aligning them with the vertical axis of thespecimenholderThis guarantees that the fibersrsquo cross-sectionrests transversally to the microscope axis since the specimenholder is perfectly aligned with this axis

Although this was a very time-consuming step it provedto be feasible and the cross-section of the vast majority of thefibers was at a horizontal plane perpendicular to the micro-scope vertical axis Therefore measurements errors at the fi-bers cross-sections geometrical parameters were minimized

100

80

60

40

20

Wei

ght l

oss (

)

0 100 200 300 400 500 600 700 800Temperature (∘C)

0

minus2

minus4

minus6

minus8

minus10

Derivative of w

eight loss (m

in)

Figure 5 Thermogravimetric behavior of the H bihai fiber Thesame overall behaviorwas also observed forE elatior andC comosusfibers

4 Conference Papers in Materials Science

1816141210

86420

Num

ber o

f fibe

rs

02 03 04 05 06 07 08 09 10Aspect ratio

(a)

1816141210

86420

Num

ber o

f fibe

rs

02 03 04 05 06 07 08 09 10Aspect ratio

(b)

1816141210

86420

Num

ber o

f fibe

rs

02 03 04 05 06 07 08 09 10Aspect ratio

(c)

Figure 6 Aspect ratio histograms from (a) E elatior (b) C comosus and (c) H bihai fibers

(a) (b)

Figure 7 Examples of the large fibersrsquo cross-section variability found for C comosus

SEM images were captured using a beam electron voltageof 20 kV on gold sputtered samples and at the secondaryelectrons imaging mode

Digital image analysis was used to characterize the fibercross-sections However due to the very irregular shape ofthe fibers and to the fact that their images were collectedseparatelymdashone by onemdashit was not possible to use a com-pletely automated analysis process as described in a previouswork [6] Here the first step of the digital image analysis was amanual outline of the fiberrsquos perimeter as shown in Figure 2After this border was delineated all the following analyses ofthe fibers could be fully automated Fifty fibers from E elatiorand C comosus and 40 from H bihai were analyzed

The parameters used to the morphometric analysis of thefibers were the true fiber area (119860

119879) obtained just by counting

the image pixels contained inside the outlined perimeterthe maximum and minimum calipers (119865max) and (119865min)corresponding respectively to the longest and to the shortestprojection of the fiber Figure 3 [12] and the aspect ratio (AR)defined as the ratio between (119865max) and (119865min) considered asa good measure of the cross-section elongation

The measurement of both maximum and minimumcalipers has also the objective to estimate a circular area ofthe cross-sections since it is a common place to assumethat the fibers have a circular cross-section when traditionalmeasurements methods such as when micrometers or othercalipers are used Since the image analysis methodology

permits the direct measurement of the true area of the cross-section it is also possible to estimate the error commitedwhen the maximum or the minimum calipers are usedas representative measures of an ldquoapparent fiber diameterrdquoThese errors can be calculated using the following equations[6]

119864119865max=

100381610038161003816100381610038161003816100381610038161003816

119860119879minus 119860119865max

119860119879

100381610038161003816100381610038161003816100381610038161003816

times 100

119864119865min=

100381610038161003816100381610038161003816100381610038161003816

119860119879minus 119860119865min

119860119879

100381610038161003816100381610038161003816100381610038161003816

times 100

(2)

where 119860119865max

and 119860119865min

are the circular areas calculatedrespectively using 119865max or 119865min as the fiber diameters

3 Results and Discussion

Figure 4 shows the results of the X-rays analysis The spectraof the three fibers are as expected similar and show thepresence of the three characteristic peaks of native cellulosenamely [13 14] (i) the peak with the highest intensity at 222∘corresponds to the diffraction of the (002) plane (ii) a broadpeak between 14∘ and 16∘ corresponds to the diffraction of

Conference Papers in Materials Science 5

times105

5

4

3

2

1

0

Are

a (120583

m2)

AreaTrue area Area from feret max Area from feret min

lowast

lowast

lowast

lowastlowastlowast

(120583m2)

AFmax AFmin

(a)

Are

a (120583

m2)

lowast

lowast

lowast

lowastlowastlowast

times106

30

25

20

15

10

05

00Area

True area Area from feret max Area from feret min(120583m2)

AFmax AFmin

(b)

40

Are

a (120583

m2)

lowast

lowast

lowast

lowastlowastlowast

times106

35

30

25

20

15

10

05

00Area

True area Area from feret max Area from feret min(120583m2)

AFmax AFmin

(c)

Figure 8 Comparison between the true fiber area directly measured by image analysis and the areas calculated assuming circular cross-sections (a) E elatior (b) C comosus and (c) H bihai fibers

both (101) and (101) planes and (iii) the peak around 34∘corresponds to the (040) plane

The crystalline index of the fibers evaluated from (1)showed no significant statistical difference between the fibersThe values obtained were 585 578 and 585 for respec-tively E elatior C comosus and H bihai fibers These valuesare similar to values reported for several other lignocellulosicfibers [15]

Figure 5 shows the thermogravimetric behavior observedfor the H bihai fiber and it is also representative of thebehavior of the other two fibers At the temperature rangebetween around 30∘C and 90∘C there is a mass loss attributedto loss of humidityThe valuesmeasured for the three types offibers are listed in Table 1 and agree with the values reportedfor several other lignocellulosic fibers [7 16 17]

Table 1 Humidity loss and peak temperature of the cellulosedecomposition of E elatior C comosus and H bihai fibers

Fiber Humidity loss Peak temperature ∘CE elatior 89 358C comosus 78 379H bihai 88 370

Theonset of the thermal degradation of the fibers definedas the temperature where a mass loss of 1 occurs at the pla-teau following the humiditymass loss began at around 230∘Cfor E elatior 240∘C for C comosus and 255∘C for H bihaiThe subsequent mass loss is mainly attributed to the thermal

6 Conference Papers in Materials Science

Table 2 Statistical comparison between the true area and the circular areas calculated using the maximum and minimum caliper valuesStudentrsquos 119905-test between the average values

Area calculated using the maximum caliper Area calculated using the minimum caliperE elatior Yes (119875 = 18119864 minus 7) Yes (119875 = 25119864 minus 6)C comosus Yes (119875 = 94119864 minus 7) Yes (119875 = 42119864 minus 5)H bihai Yes (119875 = 71119864 minus 7) Yes (119875 = 25119864 minus 5)95 confidence interval Yes means a statistically significant difference

decomposition of hemicellulose as well as to the rupture ofglycoside link of the cellulose molecule and the rupture of 120572and 120573 aryl-alkyl-ether linkages originated from the thermaldegradation reactions of lignin [18 19]

The last thermal degradation step is associated to thedegradation of cellulose and the value where the peaktemperature of the cellulose thermal degradation occurredmdashobtained from the DTG curvemdashis also listed in Table 1The values obtained closely agree with the values reportedfor the thermal degradation of cellulose from other severallignocellulosic fibers [20]

Figure 6 shows the histograms of the aspect ratio of thefibers obtained from digital image analysis results Thesehistograms show that the fibersrsquo cross-section has a largevariety of forms since AR presents a large range of values Infact one can observe that forE elatior values ranging from02to 09 with an average of 060 and a standard deviation (SD)of 015 were obtained C comosus fibers showed a similartrend with AR values ranging from 03 to 09 with an averageof 063 and a SD of 014 H bihai fibers also showed valuesfrom 03 to 09 The average value here was of 055 with a SDof 013 Figure 7 shows some cross-sections where one canclearly observe the very different shape of the fibers Besidesthe histograms of Figure 6 show that the cross-section of thefibers is preferentially elongated since AR values are smallerthan 1 AR values approaching unity mean a more equiaxialfiberrsquo cross-section

In Figure 8 the graphs compare the true area measuredby image analysis with the circular areas calculated from theminimum and maximum calipers The Studentrsquos 119905-test wasapplied assuming a 95 confidence interval and has indicatedthat there exists a significant difference between the truearea and the calculated circular areas for the three analyzedfibers These results are listed in Table 2 and show that thecircular area calculated both from the maximum or fromthe minimum caliper is statistically different from the truemeasured cross-section area

The errors between the circular areas inferred using thecalipers as ldquodiametersrdquo and the true areawere calculated using(2) Therefore for each specimen of each fiber two errorswere calculated namely 119864

119865maxand 119864

119865min when the maximum

caliper and the minimum caliper were used respectivelyFor the population of each fiber maximum minimum andaverage values of each error were then calculated Thesevalues are listed in Table 3 where one can see that errors aslarge as 300 can be generated assuming the fibers as circularobjects

Table 3 Values of 119864119865max

and 119864119865min

for the three fibers species

E elatior C comosus H bihai

119864119865max

()Maximum 273 267 337Minimum 28 37 48Average 108 116 142

119864119865min

()Maximum 69 59 61Minimum 2 5 2Average 31 23 31

4 Conclusions

The thermal and structural characteristics of fibers obtainedfrom the stems of three ornamental plants were analyzedin this work These stems are nowadays considered justas waste at the economic branch represented by the flowerand ornamental plants market However the obtained resultsindicate that these fibers have thermal stability and crystallineindex similar to the values found for other lignocellulosicfibers already used as reinforcement in polymer matrix com-posites Therefore from their structural characteristics thesefibers are possible candidates to be used as reinforcement incomposites for example at interior door panels

The fibersrsquo cross-section morphology was also analyzedand the results indicate that the values obtained by digitalimage analysis can be strongly different from the onesobtained when the fibersrsquo cross-sections are considered ascircular Determination of the aspect ratio showed that thefibers have in fact an elongated shape meaning that thecircular cross-section hypothesis can be a crude approx-imation The image analysis approach was shown to bean important tool since its use significantly increases theaccuracy of the measurements made on each fiber andalso enhanced the statistical significance of the morpho-metric parameters measured since the number of fibersanalyzed can be increased without a considerable increaseon the analysis time requested This is a key point aboutdigital image analysis since using usual techniques involvestime-consuming steps and the number of parameters mea-sured andor the number of objects analyzed is usually low

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Conference Papers in Materials Science 7

Acknowledgment

The authors acknowledge the financial support from theBrazilian Funding Agency CNPq

References

[1] J Holbery and D Houston ldquoNatural-fiber-reinforced polymercomposites in automotive applicationsrdquo JOM vol 58 no 11 pp80ndash86 2006

[2] A K Mohanty M Misra and L T Drzal ldquoSustainable bio-composites from renewable resources opportunities and chal-lenges in the greenmaterials worldrdquo Journal of Polymers and theEnvironment vol 10 no 1-2 pp 19ndash26 2002

[3] C Bergfjord and B Holst ldquoA procedure for identifying textilebast fibres using microscopy flax nettleramie hemp and juterdquoUltramicroscopy vol 110 no 9 pp 1192ndash1197 2010

[4] J L Thomason J Carruthers J Kelly and G Johnson ldquoFibrecross-section determination and variability in sisal and flax andits effects on fibre performance characterisationrdquo CompositesScience and Technology vol 71 no 7 pp 1008ndash1015 2011

[5] X W Xu and K Jayaraman ldquoAn image-processing system forthe measurement of the dimensions of natural fibre cross-sectionrdquo International Journal of Computer Applications inTechnology vol 34 no 2 p 115 2009

[6] J R M drsquoAlmeida M H P Mauricio and S PaciornikldquoEvaluation of the cross-section of lignocellulosic fibers usingdigital microscopy and image analysisrdquo Journal of CompositeMaterials vol 46 no 24 pp 3057ndash3065 2012

[7] J R M drsquoAlmeida R C M P Aquino and S N MonteiroldquoTensile mechanical properties morphological aspects andchemical characterization of piassava (Attalea funifera) fibersrdquoComposites A vol 37 no 9 pp 1473ndash1479 2006

[8] K O Reddy B R Guduri and A V Rajulu ldquoStructuralcharacterization and tensile properties of Borassus fruit fibersrdquoJournal of Applied Polymer Science vol 114 no 1 pp 603ndash6112009

[9] S M Mortazavi and M K Moghadam ldquoIntroduction of anew vegetable fiber for textile applicationrdquo Journal of AppliedPolymer Science vol 113 no 5 pp 3307ndash3312 2009

[10] B C Temer and J R M drsquoAlmeida ldquoCharacterization of thetensile behavior of Pejibaye (Bactris gasipaes) fibersrdquo Polymersfrom Renewable Resources vol 3 no 2 p 33 2012

[11] V Tserki N E Zafeiropoulos F Simon and C PanayiotouldquoA study of the effect of acetylation and propionylation surfacetreatments on natural fibresrdquo Composites A vol 36 no 8 pp1110ndash1118 2005

[12] S Paciornik and M H P Maurıcio ldquoDigital imagingrdquo in ASMHandbook Metallography and Microstructures G F V VoortEd pp 368ndash402 ASM International Materials Park OhioUSA 2004

[13] M Z Rong M Q Zhang Y Liu G C Yang and H M ZengldquoThe effect of fiber treatment on the mechanical properties ofunidirectional sisal-reinforced epoxy compositesrdquo CompositesScience and Technology vol 61 no 10 pp 1437ndash1447 2001

[14] D M R Georget P Cairns A C Smith and K W WaldronldquoCrystallinity of lyophilised carrot cell wall componentsrdquo Inter-national Journal of Biological Macromolecules vol 26 no 5 pp325ndash331 1999

[15] J F Revola A Dietrich and D A I Goring ldquoEffect of mercer-ization on the crystallite size and crystallinity index in cellulose

from different sourcesrdquo Canadian Journal of Chemistry vol 65no 8 pp 1724ndash1725 1987

[16] J R M drsquoAlmeida A L F S drsquoAlmeida and L H de CarvalholdquoMechanical morphological and structural characteristics ofcaroa (Neoglaziovia variegata) fibresrdquo Polymers and PolymerComposites vol 16 no 9 pp 589ndash595 2008

[17] A Bismarck A K Mohanty I Aranberri-Askargorta et alldquoSurface characterization of natural fibers surface propertiesand thewater up-take behavior ofmodified sisal and coir fibersrdquoGreen Chemistry vol 3 no 2 pp 100ndash107 2001

[18] B Wielage T Lampke G Marx K Nestler and D StarkeldquoThermogravimetric and differential scanning calorimetricanalysis of natural fibres and polypropylenerdquo ThermochimicaActa vol 337 no 1-2 pp 169ndash177 1999

[19] K C M Nair S Thomas and G Groeninckx ldquoThermaland dynamic mechanical analysis of polystyrene compositesreinforced with short sisal fibresrdquo Composites Science andTechnology vol 61 no 16 pp 2519ndash2529 2001

[20] A L F S drsquoAlmeida V Calado D W Barreto and J RM drsquoAlmeida ldquoEffect of surface treatments on the dynamicmechanical behavior of piassava fiber-polyestermatrix compos-itesrdquo Journal of Thermal Analysis and Calorimetry vol 103 no1 pp 179ndash184 2011

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

The Scientific World Journal

Impact Factor 173028 Days Fast Track Peer ReviewAll Subject Areas of ScienceSubmit at httpwwwtswjcom

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Conference Papers in Materials Science 3

1000

800

600

400

200

0

Lin

(cou

nts)

0 10 20 30 40 50 60 70 80 90 1002120579 (scale)

16∘

2236∘

3455∘

(a)

1575∘

222∘

347∘

1000

800

600

400

200

0

Lin

(cou

nts)

0 10 20 30 40 50 60 70 80 90 1002120579 (scale)

(b)

1485∘

22∘

3475∘

1000

800

600

400

200

0

Lin

(cou

nts)

0 10 20 30 40 50 60 70 80 90 1002120579 (scale)

(c)

Figure 4 X-rays diffractogram of the fibers (a) E elatior (b) C comosus and (c) H bihai

immersed in water for around 6 hours and were then cutusing a doctor blade as depicted in Figure 1 This simpleprocedure guarantees a smooth cross-section without defor-mation artifacts usually observed when dry fibers are cutThe cut fibers were dried at 70∘C plusmn 5∘C until constant weightand were subsequently mounted vertically at a specimenholder to have their cross-section analyzed at the SEM Atthis step the fibers were individually mounted at the sideof the cylindrical SEM specimen holder with a double facetape carefully aligning them with the vertical axis of thespecimenholderThis guarantees that the fibersrsquo cross-sectionrests transversally to the microscope axis since the specimenholder is perfectly aligned with this axis

Although this was a very time-consuming step it provedto be feasible and the cross-section of the vast majority of thefibers was at a horizontal plane perpendicular to the micro-scope vertical axis Therefore measurements errors at the fi-bers cross-sections geometrical parameters were minimized

100

80

60

40

20

Wei

ght l

oss (

)

0 100 200 300 400 500 600 700 800Temperature (∘C)

0

minus2

minus4

minus6

minus8

minus10

Derivative of w

eight loss (m

in)

Figure 5 Thermogravimetric behavior of the H bihai fiber Thesame overall behaviorwas also observed forE elatior andC comosusfibers

4 Conference Papers in Materials Science

1816141210

86420

Num

ber o

f fibe

rs

02 03 04 05 06 07 08 09 10Aspect ratio

(a)

1816141210

86420

Num

ber o

f fibe

rs

02 03 04 05 06 07 08 09 10Aspect ratio

(b)

1816141210

86420

Num

ber o

f fibe

rs

02 03 04 05 06 07 08 09 10Aspect ratio

(c)

Figure 6 Aspect ratio histograms from (a) E elatior (b) C comosus and (c) H bihai fibers

(a) (b)

Figure 7 Examples of the large fibersrsquo cross-section variability found for C comosus

SEM images were captured using a beam electron voltageof 20 kV on gold sputtered samples and at the secondaryelectrons imaging mode

Digital image analysis was used to characterize the fibercross-sections However due to the very irregular shape ofthe fibers and to the fact that their images were collectedseparatelymdashone by onemdashit was not possible to use a com-pletely automated analysis process as described in a previouswork [6] Here the first step of the digital image analysis was amanual outline of the fiberrsquos perimeter as shown in Figure 2After this border was delineated all the following analyses ofthe fibers could be fully automated Fifty fibers from E elatiorand C comosus and 40 from H bihai were analyzed

The parameters used to the morphometric analysis of thefibers were the true fiber area (119860

119879) obtained just by counting

the image pixels contained inside the outlined perimeterthe maximum and minimum calipers (119865max) and (119865min)corresponding respectively to the longest and to the shortestprojection of the fiber Figure 3 [12] and the aspect ratio (AR)defined as the ratio between (119865max) and (119865min) considered asa good measure of the cross-section elongation

The measurement of both maximum and minimumcalipers has also the objective to estimate a circular area ofthe cross-sections since it is a common place to assumethat the fibers have a circular cross-section when traditionalmeasurements methods such as when micrometers or othercalipers are used Since the image analysis methodology

permits the direct measurement of the true area of the cross-section it is also possible to estimate the error commitedwhen the maximum or the minimum calipers are usedas representative measures of an ldquoapparent fiber diameterrdquoThese errors can be calculated using the following equations[6]

119864119865max=

100381610038161003816100381610038161003816100381610038161003816

119860119879minus 119860119865max

119860119879

100381610038161003816100381610038161003816100381610038161003816

times 100

119864119865min=

100381610038161003816100381610038161003816100381610038161003816

119860119879minus 119860119865min

119860119879

100381610038161003816100381610038161003816100381610038161003816

times 100

(2)

where 119860119865max

and 119860119865min

are the circular areas calculatedrespectively using 119865max or 119865min as the fiber diameters

3 Results and Discussion

Figure 4 shows the results of the X-rays analysis The spectraof the three fibers are as expected similar and show thepresence of the three characteristic peaks of native cellulosenamely [13 14] (i) the peak with the highest intensity at 222∘corresponds to the diffraction of the (002) plane (ii) a broadpeak between 14∘ and 16∘ corresponds to the diffraction of

Conference Papers in Materials Science 5

times105

5

4

3

2

1

0

Are

a (120583

m2)

AreaTrue area Area from feret max Area from feret min

lowast

lowast

lowast

lowastlowastlowast

(120583m2)

AFmax AFmin

(a)

Are

a (120583

m2)

lowast

lowast

lowast

lowastlowastlowast

times106

30

25

20

15

10

05

00Area

True area Area from feret max Area from feret min(120583m2)

AFmax AFmin

(b)

40

Are

a (120583

m2)

lowast

lowast

lowast

lowastlowastlowast

times106

35

30

25

20

15

10

05

00Area

True area Area from feret max Area from feret min(120583m2)

AFmax AFmin

(c)

Figure 8 Comparison between the true fiber area directly measured by image analysis and the areas calculated assuming circular cross-sections (a) E elatior (b) C comosus and (c) H bihai fibers

both (101) and (101) planes and (iii) the peak around 34∘corresponds to the (040) plane

The crystalline index of the fibers evaluated from (1)showed no significant statistical difference between the fibersThe values obtained were 585 578 and 585 for respec-tively E elatior C comosus and H bihai fibers These valuesare similar to values reported for several other lignocellulosicfibers [15]

Figure 5 shows the thermogravimetric behavior observedfor the H bihai fiber and it is also representative of thebehavior of the other two fibers At the temperature rangebetween around 30∘C and 90∘C there is a mass loss attributedto loss of humidityThe valuesmeasured for the three types offibers are listed in Table 1 and agree with the values reportedfor several other lignocellulosic fibers [7 16 17]

Table 1 Humidity loss and peak temperature of the cellulosedecomposition of E elatior C comosus and H bihai fibers

Fiber Humidity loss Peak temperature ∘CE elatior 89 358C comosus 78 379H bihai 88 370

Theonset of the thermal degradation of the fibers definedas the temperature where a mass loss of 1 occurs at the pla-teau following the humiditymass loss began at around 230∘Cfor E elatior 240∘C for C comosus and 255∘C for H bihaiThe subsequent mass loss is mainly attributed to the thermal

6 Conference Papers in Materials Science

Table 2 Statistical comparison between the true area and the circular areas calculated using the maximum and minimum caliper valuesStudentrsquos 119905-test between the average values

Area calculated using the maximum caliper Area calculated using the minimum caliperE elatior Yes (119875 = 18119864 minus 7) Yes (119875 = 25119864 minus 6)C comosus Yes (119875 = 94119864 minus 7) Yes (119875 = 42119864 minus 5)H bihai Yes (119875 = 71119864 minus 7) Yes (119875 = 25119864 minus 5)95 confidence interval Yes means a statistically significant difference

decomposition of hemicellulose as well as to the rupture ofglycoside link of the cellulose molecule and the rupture of 120572and 120573 aryl-alkyl-ether linkages originated from the thermaldegradation reactions of lignin [18 19]

The last thermal degradation step is associated to thedegradation of cellulose and the value where the peaktemperature of the cellulose thermal degradation occurredmdashobtained from the DTG curvemdashis also listed in Table 1The values obtained closely agree with the values reportedfor the thermal degradation of cellulose from other severallignocellulosic fibers [20]

Figure 6 shows the histograms of the aspect ratio of thefibers obtained from digital image analysis results Thesehistograms show that the fibersrsquo cross-section has a largevariety of forms since AR presents a large range of values Infact one can observe that forE elatior values ranging from02to 09 with an average of 060 and a standard deviation (SD)of 015 were obtained C comosus fibers showed a similartrend with AR values ranging from 03 to 09 with an averageof 063 and a SD of 014 H bihai fibers also showed valuesfrom 03 to 09 The average value here was of 055 with a SDof 013 Figure 7 shows some cross-sections where one canclearly observe the very different shape of the fibers Besidesthe histograms of Figure 6 show that the cross-section of thefibers is preferentially elongated since AR values are smallerthan 1 AR values approaching unity mean a more equiaxialfiberrsquo cross-section

In Figure 8 the graphs compare the true area measuredby image analysis with the circular areas calculated from theminimum and maximum calipers The Studentrsquos 119905-test wasapplied assuming a 95 confidence interval and has indicatedthat there exists a significant difference between the truearea and the calculated circular areas for the three analyzedfibers These results are listed in Table 2 and show that thecircular area calculated both from the maximum or fromthe minimum caliper is statistically different from the truemeasured cross-section area

The errors between the circular areas inferred using thecalipers as ldquodiametersrdquo and the true areawere calculated using(2) Therefore for each specimen of each fiber two errorswere calculated namely 119864

119865maxand 119864

119865min when the maximum

caliper and the minimum caliper were used respectivelyFor the population of each fiber maximum minimum andaverage values of each error were then calculated Thesevalues are listed in Table 3 where one can see that errors aslarge as 300 can be generated assuming the fibers as circularobjects

Table 3 Values of 119864119865max

and 119864119865min

for the three fibers species

E elatior C comosus H bihai

119864119865max

()Maximum 273 267 337Minimum 28 37 48Average 108 116 142

119864119865min

()Maximum 69 59 61Minimum 2 5 2Average 31 23 31

4 Conclusions

The thermal and structural characteristics of fibers obtainedfrom the stems of three ornamental plants were analyzedin this work These stems are nowadays considered justas waste at the economic branch represented by the flowerand ornamental plants market However the obtained resultsindicate that these fibers have thermal stability and crystallineindex similar to the values found for other lignocellulosicfibers already used as reinforcement in polymer matrix com-posites Therefore from their structural characteristics thesefibers are possible candidates to be used as reinforcement incomposites for example at interior door panels

The fibersrsquo cross-section morphology was also analyzedand the results indicate that the values obtained by digitalimage analysis can be strongly different from the onesobtained when the fibersrsquo cross-sections are considered ascircular Determination of the aspect ratio showed that thefibers have in fact an elongated shape meaning that thecircular cross-section hypothesis can be a crude approx-imation The image analysis approach was shown to bean important tool since its use significantly increases theaccuracy of the measurements made on each fiber andalso enhanced the statistical significance of the morpho-metric parameters measured since the number of fibersanalyzed can be increased without a considerable increaseon the analysis time requested This is a key point aboutdigital image analysis since using usual techniques involvestime-consuming steps and the number of parameters mea-sured andor the number of objects analyzed is usually low

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Conference Papers in Materials Science 7

Acknowledgment

The authors acknowledge the financial support from theBrazilian Funding Agency CNPq

References

[1] J Holbery and D Houston ldquoNatural-fiber-reinforced polymercomposites in automotive applicationsrdquo JOM vol 58 no 11 pp80ndash86 2006

[2] A K Mohanty M Misra and L T Drzal ldquoSustainable bio-composites from renewable resources opportunities and chal-lenges in the greenmaterials worldrdquo Journal of Polymers and theEnvironment vol 10 no 1-2 pp 19ndash26 2002

[3] C Bergfjord and B Holst ldquoA procedure for identifying textilebast fibres using microscopy flax nettleramie hemp and juterdquoUltramicroscopy vol 110 no 9 pp 1192ndash1197 2010

[4] J L Thomason J Carruthers J Kelly and G Johnson ldquoFibrecross-section determination and variability in sisal and flax andits effects on fibre performance characterisationrdquo CompositesScience and Technology vol 71 no 7 pp 1008ndash1015 2011

[5] X W Xu and K Jayaraman ldquoAn image-processing system forthe measurement of the dimensions of natural fibre cross-sectionrdquo International Journal of Computer Applications inTechnology vol 34 no 2 p 115 2009

[6] J R M drsquoAlmeida M H P Mauricio and S PaciornikldquoEvaluation of the cross-section of lignocellulosic fibers usingdigital microscopy and image analysisrdquo Journal of CompositeMaterials vol 46 no 24 pp 3057ndash3065 2012

[7] J R M drsquoAlmeida R C M P Aquino and S N MonteiroldquoTensile mechanical properties morphological aspects andchemical characterization of piassava (Attalea funifera) fibersrdquoComposites A vol 37 no 9 pp 1473ndash1479 2006

[8] K O Reddy B R Guduri and A V Rajulu ldquoStructuralcharacterization and tensile properties of Borassus fruit fibersrdquoJournal of Applied Polymer Science vol 114 no 1 pp 603ndash6112009

[9] S M Mortazavi and M K Moghadam ldquoIntroduction of anew vegetable fiber for textile applicationrdquo Journal of AppliedPolymer Science vol 113 no 5 pp 3307ndash3312 2009

[10] B C Temer and J R M drsquoAlmeida ldquoCharacterization of thetensile behavior of Pejibaye (Bactris gasipaes) fibersrdquo Polymersfrom Renewable Resources vol 3 no 2 p 33 2012

[11] V Tserki N E Zafeiropoulos F Simon and C PanayiotouldquoA study of the effect of acetylation and propionylation surfacetreatments on natural fibresrdquo Composites A vol 36 no 8 pp1110ndash1118 2005

[12] S Paciornik and M H P Maurıcio ldquoDigital imagingrdquo in ASMHandbook Metallography and Microstructures G F V VoortEd pp 368ndash402 ASM International Materials Park OhioUSA 2004

[13] M Z Rong M Q Zhang Y Liu G C Yang and H M ZengldquoThe effect of fiber treatment on the mechanical properties ofunidirectional sisal-reinforced epoxy compositesrdquo CompositesScience and Technology vol 61 no 10 pp 1437ndash1447 2001

[14] D M R Georget P Cairns A C Smith and K W WaldronldquoCrystallinity of lyophilised carrot cell wall componentsrdquo Inter-national Journal of Biological Macromolecules vol 26 no 5 pp325ndash331 1999

[15] J F Revola A Dietrich and D A I Goring ldquoEffect of mercer-ization on the crystallite size and crystallinity index in cellulose

from different sourcesrdquo Canadian Journal of Chemistry vol 65no 8 pp 1724ndash1725 1987

[16] J R M drsquoAlmeida A L F S drsquoAlmeida and L H de CarvalholdquoMechanical morphological and structural characteristics ofcaroa (Neoglaziovia variegata) fibresrdquo Polymers and PolymerComposites vol 16 no 9 pp 589ndash595 2008

[17] A Bismarck A K Mohanty I Aranberri-Askargorta et alldquoSurface characterization of natural fibers surface propertiesand thewater up-take behavior ofmodified sisal and coir fibersrdquoGreen Chemistry vol 3 no 2 pp 100ndash107 2001

[18] B Wielage T Lampke G Marx K Nestler and D StarkeldquoThermogravimetric and differential scanning calorimetricanalysis of natural fibres and polypropylenerdquo ThermochimicaActa vol 337 no 1-2 pp 169ndash177 1999

[19] K C M Nair S Thomas and G Groeninckx ldquoThermaland dynamic mechanical analysis of polystyrene compositesreinforced with short sisal fibresrdquo Composites Science andTechnology vol 61 no 16 pp 2519ndash2529 2001

[20] A L F S drsquoAlmeida V Calado D W Barreto and J RM drsquoAlmeida ldquoEffect of surface treatments on the dynamicmechanical behavior of piassava fiber-polyestermatrix compos-itesrdquo Journal of Thermal Analysis and Calorimetry vol 103 no1 pp 179ndash184 2011

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

The Scientific World Journal

Impact Factor 173028 Days Fast Track Peer ReviewAll Subject Areas of ScienceSubmit at httpwwwtswjcom

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

4 Conference Papers in Materials Science

1816141210

86420

Num

ber o

f fibe

rs

02 03 04 05 06 07 08 09 10Aspect ratio

(a)

1816141210

86420

Num

ber o

f fibe

rs

02 03 04 05 06 07 08 09 10Aspect ratio

(b)

1816141210

86420

Num

ber o

f fibe

rs

02 03 04 05 06 07 08 09 10Aspect ratio

(c)

Figure 6 Aspect ratio histograms from (a) E elatior (b) C comosus and (c) H bihai fibers

(a) (b)

Figure 7 Examples of the large fibersrsquo cross-section variability found for C comosus

SEM images were captured using a beam electron voltageof 20 kV on gold sputtered samples and at the secondaryelectrons imaging mode

Digital image analysis was used to characterize the fibercross-sections However due to the very irregular shape ofthe fibers and to the fact that their images were collectedseparatelymdashone by onemdashit was not possible to use a com-pletely automated analysis process as described in a previouswork [6] Here the first step of the digital image analysis was amanual outline of the fiberrsquos perimeter as shown in Figure 2After this border was delineated all the following analyses ofthe fibers could be fully automated Fifty fibers from E elatiorand C comosus and 40 from H bihai were analyzed

The parameters used to the morphometric analysis of thefibers were the true fiber area (119860

119879) obtained just by counting

the image pixels contained inside the outlined perimeterthe maximum and minimum calipers (119865max) and (119865min)corresponding respectively to the longest and to the shortestprojection of the fiber Figure 3 [12] and the aspect ratio (AR)defined as the ratio between (119865max) and (119865min) considered asa good measure of the cross-section elongation

The measurement of both maximum and minimumcalipers has also the objective to estimate a circular area ofthe cross-sections since it is a common place to assumethat the fibers have a circular cross-section when traditionalmeasurements methods such as when micrometers or othercalipers are used Since the image analysis methodology

permits the direct measurement of the true area of the cross-section it is also possible to estimate the error commitedwhen the maximum or the minimum calipers are usedas representative measures of an ldquoapparent fiber diameterrdquoThese errors can be calculated using the following equations[6]

119864119865max=

100381610038161003816100381610038161003816100381610038161003816

119860119879minus 119860119865max

119860119879

100381610038161003816100381610038161003816100381610038161003816

times 100

119864119865min=

100381610038161003816100381610038161003816100381610038161003816

119860119879minus 119860119865min

119860119879

100381610038161003816100381610038161003816100381610038161003816

times 100

(2)

where 119860119865max

and 119860119865min

are the circular areas calculatedrespectively using 119865max or 119865min as the fiber diameters

3 Results and Discussion

Figure 4 shows the results of the X-rays analysis The spectraof the three fibers are as expected similar and show thepresence of the three characteristic peaks of native cellulosenamely [13 14] (i) the peak with the highest intensity at 222∘corresponds to the diffraction of the (002) plane (ii) a broadpeak between 14∘ and 16∘ corresponds to the diffraction of

Conference Papers in Materials Science 5

times105

5

4

3

2

1

0

Are

a (120583

m2)

AreaTrue area Area from feret max Area from feret min

lowast

lowast

lowast

lowastlowastlowast

(120583m2)

AFmax AFmin

(a)

Are

a (120583

m2)

lowast

lowast

lowast

lowastlowastlowast

times106

30

25

20

15

10

05

00Area

True area Area from feret max Area from feret min(120583m2)

AFmax AFmin

(b)

40

Are

a (120583

m2)

lowast

lowast

lowast

lowastlowastlowast

times106

35

30

25

20

15

10

05

00Area

True area Area from feret max Area from feret min(120583m2)

AFmax AFmin

(c)

Figure 8 Comparison between the true fiber area directly measured by image analysis and the areas calculated assuming circular cross-sections (a) E elatior (b) C comosus and (c) H bihai fibers

both (101) and (101) planes and (iii) the peak around 34∘corresponds to the (040) plane

The crystalline index of the fibers evaluated from (1)showed no significant statistical difference between the fibersThe values obtained were 585 578 and 585 for respec-tively E elatior C comosus and H bihai fibers These valuesare similar to values reported for several other lignocellulosicfibers [15]

Figure 5 shows the thermogravimetric behavior observedfor the H bihai fiber and it is also representative of thebehavior of the other two fibers At the temperature rangebetween around 30∘C and 90∘C there is a mass loss attributedto loss of humidityThe valuesmeasured for the three types offibers are listed in Table 1 and agree with the values reportedfor several other lignocellulosic fibers [7 16 17]

Table 1 Humidity loss and peak temperature of the cellulosedecomposition of E elatior C comosus and H bihai fibers

Fiber Humidity loss Peak temperature ∘CE elatior 89 358C comosus 78 379H bihai 88 370

Theonset of the thermal degradation of the fibers definedas the temperature where a mass loss of 1 occurs at the pla-teau following the humiditymass loss began at around 230∘Cfor E elatior 240∘C for C comosus and 255∘C for H bihaiThe subsequent mass loss is mainly attributed to the thermal

6 Conference Papers in Materials Science

Table 2 Statistical comparison between the true area and the circular areas calculated using the maximum and minimum caliper valuesStudentrsquos 119905-test between the average values

Area calculated using the maximum caliper Area calculated using the minimum caliperE elatior Yes (119875 = 18119864 minus 7) Yes (119875 = 25119864 minus 6)C comosus Yes (119875 = 94119864 minus 7) Yes (119875 = 42119864 minus 5)H bihai Yes (119875 = 71119864 minus 7) Yes (119875 = 25119864 minus 5)95 confidence interval Yes means a statistically significant difference

decomposition of hemicellulose as well as to the rupture ofglycoside link of the cellulose molecule and the rupture of 120572and 120573 aryl-alkyl-ether linkages originated from the thermaldegradation reactions of lignin [18 19]

The last thermal degradation step is associated to thedegradation of cellulose and the value where the peaktemperature of the cellulose thermal degradation occurredmdashobtained from the DTG curvemdashis also listed in Table 1The values obtained closely agree with the values reportedfor the thermal degradation of cellulose from other severallignocellulosic fibers [20]

Figure 6 shows the histograms of the aspect ratio of thefibers obtained from digital image analysis results Thesehistograms show that the fibersrsquo cross-section has a largevariety of forms since AR presents a large range of values Infact one can observe that forE elatior values ranging from02to 09 with an average of 060 and a standard deviation (SD)of 015 were obtained C comosus fibers showed a similartrend with AR values ranging from 03 to 09 with an averageof 063 and a SD of 014 H bihai fibers also showed valuesfrom 03 to 09 The average value here was of 055 with a SDof 013 Figure 7 shows some cross-sections where one canclearly observe the very different shape of the fibers Besidesthe histograms of Figure 6 show that the cross-section of thefibers is preferentially elongated since AR values are smallerthan 1 AR values approaching unity mean a more equiaxialfiberrsquo cross-section

In Figure 8 the graphs compare the true area measuredby image analysis with the circular areas calculated from theminimum and maximum calipers The Studentrsquos 119905-test wasapplied assuming a 95 confidence interval and has indicatedthat there exists a significant difference between the truearea and the calculated circular areas for the three analyzedfibers These results are listed in Table 2 and show that thecircular area calculated both from the maximum or fromthe minimum caliper is statistically different from the truemeasured cross-section area

The errors between the circular areas inferred using thecalipers as ldquodiametersrdquo and the true areawere calculated using(2) Therefore for each specimen of each fiber two errorswere calculated namely 119864

119865maxand 119864

119865min when the maximum

caliper and the minimum caliper were used respectivelyFor the population of each fiber maximum minimum andaverage values of each error were then calculated Thesevalues are listed in Table 3 where one can see that errors aslarge as 300 can be generated assuming the fibers as circularobjects

Table 3 Values of 119864119865max

and 119864119865min

for the three fibers species

E elatior C comosus H bihai

119864119865max

()Maximum 273 267 337Minimum 28 37 48Average 108 116 142

119864119865min

()Maximum 69 59 61Minimum 2 5 2Average 31 23 31

4 Conclusions

The thermal and structural characteristics of fibers obtainedfrom the stems of three ornamental plants were analyzedin this work These stems are nowadays considered justas waste at the economic branch represented by the flowerand ornamental plants market However the obtained resultsindicate that these fibers have thermal stability and crystallineindex similar to the values found for other lignocellulosicfibers already used as reinforcement in polymer matrix com-posites Therefore from their structural characteristics thesefibers are possible candidates to be used as reinforcement incomposites for example at interior door panels

The fibersrsquo cross-section morphology was also analyzedand the results indicate that the values obtained by digitalimage analysis can be strongly different from the onesobtained when the fibersrsquo cross-sections are considered ascircular Determination of the aspect ratio showed that thefibers have in fact an elongated shape meaning that thecircular cross-section hypothesis can be a crude approx-imation The image analysis approach was shown to bean important tool since its use significantly increases theaccuracy of the measurements made on each fiber andalso enhanced the statistical significance of the morpho-metric parameters measured since the number of fibersanalyzed can be increased without a considerable increaseon the analysis time requested This is a key point aboutdigital image analysis since using usual techniques involvestime-consuming steps and the number of parameters mea-sured andor the number of objects analyzed is usually low

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Conference Papers in Materials Science 7

Acknowledgment

The authors acknowledge the financial support from theBrazilian Funding Agency CNPq

References

[1] J Holbery and D Houston ldquoNatural-fiber-reinforced polymercomposites in automotive applicationsrdquo JOM vol 58 no 11 pp80ndash86 2006

[2] A K Mohanty M Misra and L T Drzal ldquoSustainable bio-composites from renewable resources opportunities and chal-lenges in the greenmaterials worldrdquo Journal of Polymers and theEnvironment vol 10 no 1-2 pp 19ndash26 2002

[3] C Bergfjord and B Holst ldquoA procedure for identifying textilebast fibres using microscopy flax nettleramie hemp and juterdquoUltramicroscopy vol 110 no 9 pp 1192ndash1197 2010

[4] J L Thomason J Carruthers J Kelly and G Johnson ldquoFibrecross-section determination and variability in sisal and flax andits effects on fibre performance characterisationrdquo CompositesScience and Technology vol 71 no 7 pp 1008ndash1015 2011

[5] X W Xu and K Jayaraman ldquoAn image-processing system forthe measurement of the dimensions of natural fibre cross-sectionrdquo International Journal of Computer Applications inTechnology vol 34 no 2 p 115 2009

[6] J R M drsquoAlmeida M H P Mauricio and S PaciornikldquoEvaluation of the cross-section of lignocellulosic fibers usingdigital microscopy and image analysisrdquo Journal of CompositeMaterials vol 46 no 24 pp 3057ndash3065 2012

[7] J R M drsquoAlmeida R C M P Aquino and S N MonteiroldquoTensile mechanical properties morphological aspects andchemical characterization of piassava (Attalea funifera) fibersrdquoComposites A vol 37 no 9 pp 1473ndash1479 2006

[8] K O Reddy B R Guduri and A V Rajulu ldquoStructuralcharacterization and tensile properties of Borassus fruit fibersrdquoJournal of Applied Polymer Science vol 114 no 1 pp 603ndash6112009

[9] S M Mortazavi and M K Moghadam ldquoIntroduction of anew vegetable fiber for textile applicationrdquo Journal of AppliedPolymer Science vol 113 no 5 pp 3307ndash3312 2009

[10] B C Temer and J R M drsquoAlmeida ldquoCharacterization of thetensile behavior of Pejibaye (Bactris gasipaes) fibersrdquo Polymersfrom Renewable Resources vol 3 no 2 p 33 2012

[11] V Tserki N E Zafeiropoulos F Simon and C PanayiotouldquoA study of the effect of acetylation and propionylation surfacetreatments on natural fibresrdquo Composites A vol 36 no 8 pp1110ndash1118 2005

[12] S Paciornik and M H P Maurıcio ldquoDigital imagingrdquo in ASMHandbook Metallography and Microstructures G F V VoortEd pp 368ndash402 ASM International Materials Park OhioUSA 2004

[13] M Z Rong M Q Zhang Y Liu G C Yang and H M ZengldquoThe effect of fiber treatment on the mechanical properties ofunidirectional sisal-reinforced epoxy compositesrdquo CompositesScience and Technology vol 61 no 10 pp 1437ndash1447 2001

[14] D M R Georget P Cairns A C Smith and K W WaldronldquoCrystallinity of lyophilised carrot cell wall componentsrdquo Inter-national Journal of Biological Macromolecules vol 26 no 5 pp325ndash331 1999

[15] J F Revola A Dietrich and D A I Goring ldquoEffect of mercer-ization on the crystallite size and crystallinity index in cellulose

from different sourcesrdquo Canadian Journal of Chemistry vol 65no 8 pp 1724ndash1725 1987

[16] J R M drsquoAlmeida A L F S drsquoAlmeida and L H de CarvalholdquoMechanical morphological and structural characteristics ofcaroa (Neoglaziovia variegata) fibresrdquo Polymers and PolymerComposites vol 16 no 9 pp 589ndash595 2008

[17] A Bismarck A K Mohanty I Aranberri-Askargorta et alldquoSurface characterization of natural fibers surface propertiesand thewater up-take behavior ofmodified sisal and coir fibersrdquoGreen Chemistry vol 3 no 2 pp 100ndash107 2001

[18] B Wielage T Lampke G Marx K Nestler and D StarkeldquoThermogravimetric and differential scanning calorimetricanalysis of natural fibres and polypropylenerdquo ThermochimicaActa vol 337 no 1-2 pp 169ndash177 1999

[19] K C M Nair S Thomas and G Groeninckx ldquoThermaland dynamic mechanical analysis of polystyrene compositesreinforced with short sisal fibresrdquo Composites Science andTechnology vol 61 no 16 pp 2519ndash2529 2001

[20] A L F S drsquoAlmeida V Calado D W Barreto and J RM drsquoAlmeida ldquoEffect of surface treatments on the dynamicmechanical behavior of piassava fiber-polyestermatrix compos-itesrdquo Journal of Thermal Analysis and Calorimetry vol 103 no1 pp 179ndash184 2011

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

The Scientific World Journal

Impact Factor 173028 Days Fast Track Peer ReviewAll Subject Areas of ScienceSubmit at httpwwwtswjcom

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Conference Papers in Materials Science 5

times105

5

4

3

2

1

0

Are

a (120583

m2)

AreaTrue area Area from feret max Area from feret min

lowast

lowast

lowast

lowastlowastlowast

(120583m2)

AFmax AFmin

(a)

Are

a (120583

m2)

lowast

lowast

lowast

lowastlowastlowast

times106

30

25

20

15

10

05

00Area

True area Area from feret max Area from feret min(120583m2)

AFmax AFmin

(b)

40

Are

a (120583

m2)

lowast

lowast

lowast

lowastlowastlowast

times106

35

30

25

20

15

10

05

00Area

True area Area from feret max Area from feret min(120583m2)

AFmax AFmin

(c)

Figure 8 Comparison between the true fiber area directly measured by image analysis and the areas calculated assuming circular cross-sections (a) E elatior (b) C comosus and (c) H bihai fibers

both (101) and (101) planes and (iii) the peak around 34∘corresponds to the (040) plane

The crystalline index of the fibers evaluated from (1)showed no significant statistical difference between the fibersThe values obtained were 585 578 and 585 for respec-tively E elatior C comosus and H bihai fibers These valuesare similar to values reported for several other lignocellulosicfibers [15]

Figure 5 shows the thermogravimetric behavior observedfor the H bihai fiber and it is also representative of thebehavior of the other two fibers At the temperature rangebetween around 30∘C and 90∘C there is a mass loss attributedto loss of humidityThe valuesmeasured for the three types offibers are listed in Table 1 and agree with the values reportedfor several other lignocellulosic fibers [7 16 17]

Table 1 Humidity loss and peak temperature of the cellulosedecomposition of E elatior C comosus and H bihai fibers

Fiber Humidity loss Peak temperature ∘CE elatior 89 358C comosus 78 379H bihai 88 370

Theonset of the thermal degradation of the fibers definedas the temperature where a mass loss of 1 occurs at the pla-teau following the humiditymass loss began at around 230∘Cfor E elatior 240∘C for C comosus and 255∘C for H bihaiThe subsequent mass loss is mainly attributed to the thermal

6 Conference Papers in Materials Science

Table 2 Statistical comparison between the true area and the circular areas calculated using the maximum and minimum caliper valuesStudentrsquos 119905-test between the average values

Area calculated using the maximum caliper Area calculated using the minimum caliperE elatior Yes (119875 = 18119864 minus 7) Yes (119875 = 25119864 minus 6)C comosus Yes (119875 = 94119864 minus 7) Yes (119875 = 42119864 minus 5)H bihai Yes (119875 = 71119864 minus 7) Yes (119875 = 25119864 minus 5)95 confidence interval Yes means a statistically significant difference

decomposition of hemicellulose as well as to the rupture ofglycoside link of the cellulose molecule and the rupture of 120572and 120573 aryl-alkyl-ether linkages originated from the thermaldegradation reactions of lignin [18 19]

The last thermal degradation step is associated to thedegradation of cellulose and the value where the peaktemperature of the cellulose thermal degradation occurredmdashobtained from the DTG curvemdashis also listed in Table 1The values obtained closely agree with the values reportedfor the thermal degradation of cellulose from other severallignocellulosic fibers [20]

Figure 6 shows the histograms of the aspect ratio of thefibers obtained from digital image analysis results Thesehistograms show that the fibersrsquo cross-section has a largevariety of forms since AR presents a large range of values Infact one can observe that forE elatior values ranging from02to 09 with an average of 060 and a standard deviation (SD)of 015 were obtained C comosus fibers showed a similartrend with AR values ranging from 03 to 09 with an averageof 063 and a SD of 014 H bihai fibers also showed valuesfrom 03 to 09 The average value here was of 055 with a SDof 013 Figure 7 shows some cross-sections where one canclearly observe the very different shape of the fibers Besidesthe histograms of Figure 6 show that the cross-section of thefibers is preferentially elongated since AR values are smallerthan 1 AR values approaching unity mean a more equiaxialfiberrsquo cross-section

In Figure 8 the graphs compare the true area measuredby image analysis with the circular areas calculated from theminimum and maximum calipers The Studentrsquos 119905-test wasapplied assuming a 95 confidence interval and has indicatedthat there exists a significant difference between the truearea and the calculated circular areas for the three analyzedfibers These results are listed in Table 2 and show that thecircular area calculated both from the maximum or fromthe minimum caliper is statistically different from the truemeasured cross-section area

The errors between the circular areas inferred using thecalipers as ldquodiametersrdquo and the true areawere calculated using(2) Therefore for each specimen of each fiber two errorswere calculated namely 119864

119865maxand 119864

119865min when the maximum

caliper and the minimum caliper were used respectivelyFor the population of each fiber maximum minimum andaverage values of each error were then calculated Thesevalues are listed in Table 3 where one can see that errors aslarge as 300 can be generated assuming the fibers as circularobjects

Table 3 Values of 119864119865max

and 119864119865min

for the three fibers species

E elatior C comosus H bihai

119864119865max

()Maximum 273 267 337Minimum 28 37 48Average 108 116 142

119864119865min

()Maximum 69 59 61Minimum 2 5 2Average 31 23 31

4 Conclusions

The thermal and structural characteristics of fibers obtainedfrom the stems of three ornamental plants were analyzedin this work These stems are nowadays considered justas waste at the economic branch represented by the flowerand ornamental plants market However the obtained resultsindicate that these fibers have thermal stability and crystallineindex similar to the values found for other lignocellulosicfibers already used as reinforcement in polymer matrix com-posites Therefore from their structural characteristics thesefibers are possible candidates to be used as reinforcement incomposites for example at interior door panels

The fibersrsquo cross-section morphology was also analyzedand the results indicate that the values obtained by digitalimage analysis can be strongly different from the onesobtained when the fibersrsquo cross-sections are considered ascircular Determination of the aspect ratio showed that thefibers have in fact an elongated shape meaning that thecircular cross-section hypothesis can be a crude approx-imation The image analysis approach was shown to bean important tool since its use significantly increases theaccuracy of the measurements made on each fiber andalso enhanced the statistical significance of the morpho-metric parameters measured since the number of fibersanalyzed can be increased without a considerable increaseon the analysis time requested This is a key point aboutdigital image analysis since using usual techniques involvestime-consuming steps and the number of parameters mea-sured andor the number of objects analyzed is usually low

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Conference Papers in Materials Science 7

Acknowledgment

The authors acknowledge the financial support from theBrazilian Funding Agency CNPq

References

[1] J Holbery and D Houston ldquoNatural-fiber-reinforced polymercomposites in automotive applicationsrdquo JOM vol 58 no 11 pp80ndash86 2006

[2] A K Mohanty M Misra and L T Drzal ldquoSustainable bio-composites from renewable resources opportunities and chal-lenges in the greenmaterials worldrdquo Journal of Polymers and theEnvironment vol 10 no 1-2 pp 19ndash26 2002

[3] C Bergfjord and B Holst ldquoA procedure for identifying textilebast fibres using microscopy flax nettleramie hemp and juterdquoUltramicroscopy vol 110 no 9 pp 1192ndash1197 2010

[4] J L Thomason J Carruthers J Kelly and G Johnson ldquoFibrecross-section determination and variability in sisal and flax andits effects on fibre performance characterisationrdquo CompositesScience and Technology vol 71 no 7 pp 1008ndash1015 2011

[5] X W Xu and K Jayaraman ldquoAn image-processing system forthe measurement of the dimensions of natural fibre cross-sectionrdquo International Journal of Computer Applications inTechnology vol 34 no 2 p 115 2009

[6] J R M drsquoAlmeida M H P Mauricio and S PaciornikldquoEvaluation of the cross-section of lignocellulosic fibers usingdigital microscopy and image analysisrdquo Journal of CompositeMaterials vol 46 no 24 pp 3057ndash3065 2012

[7] J R M drsquoAlmeida R C M P Aquino and S N MonteiroldquoTensile mechanical properties morphological aspects andchemical characterization of piassava (Attalea funifera) fibersrdquoComposites A vol 37 no 9 pp 1473ndash1479 2006

[8] K O Reddy B R Guduri and A V Rajulu ldquoStructuralcharacterization and tensile properties of Borassus fruit fibersrdquoJournal of Applied Polymer Science vol 114 no 1 pp 603ndash6112009

[9] S M Mortazavi and M K Moghadam ldquoIntroduction of anew vegetable fiber for textile applicationrdquo Journal of AppliedPolymer Science vol 113 no 5 pp 3307ndash3312 2009

[10] B C Temer and J R M drsquoAlmeida ldquoCharacterization of thetensile behavior of Pejibaye (Bactris gasipaes) fibersrdquo Polymersfrom Renewable Resources vol 3 no 2 p 33 2012

[11] V Tserki N E Zafeiropoulos F Simon and C PanayiotouldquoA study of the effect of acetylation and propionylation surfacetreatments on natural fibresrdquo Composites A vol 36 no 8 pp1110ndash1118 2005

[12] S Paciornik and M H P Maurıcio ldquoDigital imagingrdquo in ASMHandbook Metallography and Microstructures G F V VoortEd pp 368ndash402 ASM International Materials Park OhioUSA 2004

[13] M Z Rong M Q Zhang Y Liu G C Yang and H M ZengldquoThe effect of fiber treatment on the mechanical properties ofunidirectional sisal-reinforced epoxy compositesrdquo CompositesScience and Technology vol 61 no 10 pp 1437ndash1447 2001

[14] D M R Georget P Cairns A C Smith and K W WaldronldquoCrystallinity of lyophilised carrot cell wall componentsrdquo Inter-national Journal of Biological Macromolecules vol 26 no 5 pp325ndash331 1999

[15] J F Revola A Dietrich and D A I Goring ldquoEffect of mercer-ization on the crystallite size and crystallinity index in cellulose

from different sourcesrdquo Canadian Journal of Chemistry vol 65no 8 pp 1724ndash1725 1987

[16] J R M drsquoAlmeida A L F S drsquoAlmeida and L H de CarvalholdquoMechanical morphological and structural characteristics ofcaroa (Neoglaziovia variegata) fibresrdquo Polymers and PolymerComposites vol 16 no 9 pp 589ndash595 2008

[17] A Bismarck A K Mohanty I Aranberri-Askargorta et alldquoSurface characterization of natural fibers surface propertiesand thewater up-take behavior ofmodified sisal and coir fibersrdquoGreen Chemistry vol 3 no 2 pp 100ndash107 2001

[18] B Wielage T Lampke G Marx K Nestler and D StarkeldquoThermogravimetric and differential scanning calorimetricanalysis of natural fibres and polypropylenerdquo ThermochimicaActa vol 337 no 1-2 pp 169ndash177 1999

[19] K C M Nair S Thomas and G Groeninckx ldquoThermaland dynamic mechanical analysis of polystyrene compositesreinforced with short sisal fibresrdquo Composites Science andTechnology vol 61 no 16 pp 2519ndash2529 2001

[20] A L F S drsquoAlmeida V Calado D W Barreto and J RM drsquoAlmeida ldquoEffect of surface treatments on the dynamicmechanical behavior of piassava fiber-polyestermatrix compos-itesrdquo Journal of Thermal Analysis and Calorimetry vol 103 no1 pp 179ndash184 2011

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

The Scientific World Journal

Impact Factor 173028 Days Fast Track Peer ReviewAll Subject Areas of ScienceSubmit at httpwwwtswjcom

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

6 Conference Papers in Materials Science

Table 2 Statistical comparison between the true area and the circular areas calculated using the maximum and minimum caliper valuesStudentrsquos 119905-test between the average values

Area calculated using the maximum caliper Area calculated using the minimum caliperE elatior Yes (119875 = 18119864 minus 7) Yes (119875 = 25119864 minus 6)C comosus Yes (119875 = 94119864 minus 7) Yes (119875 = 42119864 minus 5)H bihai Yes (119875 = 71119864 minus 7) Yes (119875 = 25119864 minus 5)95 confidence interval Yes means a statistically significant difference

decomposition of hemicellulose as well as to the rupture ofglycoside link of the cellulose molecule and the rupture of 120572and 120573 aryl-alkyl-ether linkages originated from the thermaldegradation reactions of lignin [18 19]

The last thermal degradation step is associated to thedegradation of cellulose and the value where the peaktemperature of the cellulose thermal degradation occurredmdashobtained from the DTG curvemdashis also listed in Table 1The values obtained closely agree with the values reportedfor the thermal degradation of cellulose from other severallignocellulosic fibers [20]

Figure 6 shows the histograms of the aspect ratio of thefibers obtained from digital image analysis results Thesehistograms show that the fibersrsquo cross-section has a largevariety of forms since AR presents a large range of values Infact one can observe that forE elatior values ranging from02to 09 with an average of 060 and a standard deviation (SD)of 015 were obtained C comosus fibers showed a similartrend with AR values ranging from 03 to 09 with an averageof 063 and a SD of 014 H bihai fibers also showed valuesfrom 03 to 09 The average value here was of 055 with a SDof 013 Figure 7 shows some cross-sections where one canclearly observe the very different shape of the fibers Besidesthe histograms of Figure 6 show that the cross-section of thefibers is preferentially elongated since AR values are smallerthan 1 AR values approaching unity mean a more equiaxialfiberrsquo cross-section

In Figure 8 the graphs compare the true area measuredby image analysis with the circular areas calculated from theminimum and maximum calipers The Studentrsquos 119905-test wasapplied assuming a 95 confidence interval and has indicatedthat there exists a significant difference between the truearea and the calculated circular areas for the three analyzedfibers These results are listed in Table 2 and show that thecircular area calculated both from the maximum or fromthe minimum caliper is statistically different from the truemeasured cross-section area

The errors between the circular areas inferred using thecalipers as ldquodiametersrdquo and the true areawere calculated using(2) Therefore for each specimen of each fiber two errorswere calculated namely 119864

119865maxand 119864

119865min when the maximum

caliper and the minimum caliper were used respectivelyFor the population of each fiber maximum minimum andaverage values of each error were then calculated Thesevalues are listed in Table 3 where one can see that errors aslarge as 300 can be generated assuming the fibers as circularobjects

Table 3 Values of 119864119865max

and 119864119865min

for the three fibers species

E elatior C comosus H bihai

119864119865max

()Maximum 273 267 337Minimum 28 37 48Average 108 116 142

119864119865min

()Maximum 69 59 61Minimum 2 5 2Average 31 23 31

4 Conclusions

The thermal and structural characteristics of fibers obtainedfrom the stems of three ornamental plants were analyzedin this work These stems are nowadays considered justas waste at the economic branch represented by the flowerand ornamental plants market However the obtained resultsindicate that these fibers have thermal stability and crystallineindex similar to the values found for other lignocellulosicfibers already used as reinforcement in polymer matrix com-posites Therefore from their structural characteristics thesefibers are possible candidates to be used as reinforcement incomposites for example at interior door panels

The fibersrsquo cross-section morphology was also analyzedand the results indicate that the values obtained by digitalimage analysis can be strongly different from the onesobtained when the fibersrsquo cross-sections are considered ascircular Determination of the aspect ratio showed that thefibers have in fact an elongated shape meaning that thecircular cross-section hypothesis can be a crude approx-imation The image analysis approach was shown to bean important tool since its use significantly increases theaccuracy of the measurements made on each fiber andalso enhanced the statistical significance of the morpho-metric parameters measured since the number of fibersanalyzed can be increased without a considerable increaseon the analysis time requested This is a key point aboutdigital image analysis since using usual techniques involvestime-consuming steps and the number of parameters mea-sured andor the number of objects analyzed is usually low

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Conference Papers in Materials Science 7

Acknowledgment

The authors acknowledge the financial support from theBrazilian Funding Agency CNPq

References

[1] J Holbery and D Houston ldquoNatural-fiber-reinforced polymercomposites in automotive applicationsrdquo JOM vol 58 no 11 pp80ndash86 2006

[2] A K Mohanty M Misra and L T Drzal ldquoSustainable bio-composites from renewable resources opportunities and chal-lenges in the greenmaterials worldrdquo Journal of Polymers and theEnvironment vol 10 no 1-2 pp 19ndash26 2002

[3] C Bergfjord and B Holst ldquoA procedure for identifying textilebast fibres using microscopy flax nettleramie hemp and juterdquoUltramicroscopy vol 110 no 9 pp 1192ndash1197 2010

[4] J L Thomason J Carruthers J Kelly and G Johnson ldquoFibrecross-section determination and variability in sisal and flax andits effects on fibre performance characterisationrdquo CompositesScience and Technology vol 71 no 7 pp 1008ndash1015 2011

[5] X W Xu and K Jayaraman ldquoAn image-processing system forthe measurement of the dimensions of natural fibre cross-sectionrdquo International Journal of Computer Applications inTechnology vol 34 no 2 p 115 2009

[6] J R M drsquoAlmeida M H P Mauricio and S PaciornikldquoEvaluation of the cross-section of lignocellulosic fibers usingdigital microscopy and image analysisrdquo Journal of CompositeMaterials vol 46 no 24 pp 3057ndash3065 2012

[7] J R M drsquoAlmeida R C M P Aquino and S N MonteiroldquoTensile mechanical properties morphological aspects andchemical characterization of piassava (Attalea funifera) fibersrdquoComposites A vol 37 no 9 pp 1473ndash1479 2006

[8] K O Reddy B R Guduri and A V Rajulu ldquoStructuralcharacterization and tensile properties of Borassus fruit fibersrdquoJournal of Applied Polymer Science vol 114 no 1 pp 603ndash6112009

[9] S M Mortazavi and M K Moghadam ldquoIntroduction of anew vegetable fiber for textile applicationrdquo Journal of AppliedPolymer Science vol 113 no 5 pp 3307ndash3312 2009

[10] B C Temer and J R M drsquoAlmeida ldquoCharacterization of thetensile behavior of Pejibaye (Bactris gasipaes) fibersrdquo Polymersfrom Renewable Resources vol 3 no 2 p 33 2012

[11] V Tserki N E Zafeiropoulos F Simon and C PanayiotouldquoA study of the effect of acetylation and propionylation surfacetreatments on natural fibresrdquo Composites A vol 36 no 8 pp1110ndash1118 2005

[12] S Paciornik and M H P Maurıcio ldquoDigital imagingrdquo in ASMHandbook Metallography and Microstructures G F V VoortEd pp 368ndash402 ASM International Materials Park OhioUSA 2004

[13] M Z Rong M Q Zhang Y Liu G C Yang and H M ZengldquoThe effect of fiber treatment on the mechanical properties ofunidirectional sisal-reinforced epoxy compositesrdquo CompositesScience and Technology vol 61 no 10 pp 1437ndash1447 2001

[14] D M R Georget P Cairns A C Smith and K W WaldronldquoCrystallinity of lyophilised carrot cell wall componentsrdquo Inter-national Journal of Biological Macromolecules vol 26 no 5 pp325ndash331 1999

[15] J F Revola A Dietrich and D A I Goring ldquoEffect of mercer-ization on the crystallite size and crystallinity index in cellulose

from different sourcesrdquo Canadian Journal of Chemistry vol 65no 8 pp 1724ndash1725 1987

[16] J R M drsquoAlmeida A L F S drsquoAlmeida and L H de CarvalholdquoMechanical morphological and structural characteristics ofcaroa (Neoglaziovia variegata) fibresrdquo Polymers and PolymerComposites vol 16 no 9 pp 589ndash595 2008

[17] A Bismarck A K Mohanty I Aranberri-Askargorta et alldquoSurface characterization of natural fibers surface propertiesand thewater up-take behavior ofmodified sisal and coir fibersrdquoGreen Chemistry vol 3 no 2 pp 100ndash107 2001

[18] B Wielage T Lampke G Marx K Nestler and D StarkeldquoThermogravimetric and differential scanning calorimetricanalysis of natural fibres and polypropylenerdquo ThermochimicaActa vol 337 no 1-2 pp 169ndash177 1999

[19] K C M Nair S Thomas and G Groeninckx ldquoThermaland dynamic mechanical analysis of polystyrene compositesreinforced with short sisal fibresrdquo Composites Science andTechnology vol 61 no 16 pp 2519ndash2529 2001

[20] A L F S drsquoAlmeida V Calado D W Barreto and J RM drsquoAlmeida ldquoEffect of surface treatments on the dynamicmechanical behavior of piassava fiber-polyestermatrix compos-itesrdquo Journal of Thermal Analysis and Calorimetry vol 103 no1 pp 179ndash184 2011

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

The Scientific World Journal

Impact Factor 173028 Days Fast Track Peer ReviewAll Subject Areas of ScienceSubmit at httpwwwtswjcom

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Conference Papers in Materials Science 7

Acknowledgment

The authors acknowledge the financial support from theBrazilian Funding Agency CNPq

References

[1] J Holbery and D Houston ldquoNatural-fiber-reinforced polymercomposites in automotive applicationsrdquo JOM vol 58 no 11 pp80ndash86 2006

[2] A K Mohanty M Misra and L T Drzal ldquoSustainable bio-composites from renewable resources opportunities and chal-lenges in the greenmaterials worldrdquo Journal of Polymers and theEnvironment vol 10 no 1-2 pp 19ndash26 2002

[3] C Bergfjord and B Holst ldquoA procedure for identifying textilebast fibres using microscopy flax nettleramie hemp and juterdquoUltramicroscopy vol 110 no 9 pp 1192ndash1197 2010

[4] J L Thomason J Carruthers J Kelly and G Johnson ldquoFibrecross-section determination and variability in sisal and flax andits effects on fibre performance characterisationrdquo CompositesScience and Technology vol 71 no 7 pp 1008ndash1015 2011

[5] X W Xu and K Jayaraman ldquoAn image-processing system forthe measurement of the dimensions of natural fibre cross-sectionrdquo International Journal of Computer Applications inTechnology vol 34 no 2 p 115 2009

[6] J R M drsquoAlmeida M H P Mauricio and S PaciornikldquoEvaluation of the cross-section of lignocellulosic fibers usingdigital microscopy and image analysisrdquo Journal of CompositeMaterials vol 46 no 24 pp 3057ndash3065 2012

[7] J R M drsquoAlmeida R C M P Aquino and S N MonteiroldquoTensile mechanical properties morphological aspects andchemical characterization of piassava (Attalea funifera) fibersrdquoComposites A vol 37 no 9 pp 1473ndash1479 2006

[8] K O Reddy B R Guduri and A V Rajulu ldquoStructuralcharacterization and tensile properties of Borassus fruit fibersrdquoJournal of Applied Polymer Science vol 114 no 1 pp 603ndash6112009

[9] S M Mortazavi and M K Moghadam ldquoIntroduction of anew vegetable fiber for textile applicationrdquo Journal of AppliedPolymer Science vol 113 no 5 pp 3307ndash3312 2009

[10] B C Temer and J R M drsquoAlmeida ldquoCharacterization of thetensile behavior of Pejibaye (Bactris gasipaes) fibersrdquo Polymersfrom Renewable Resources vol 3 no 2 p 33 2012

[11] V Tserki N E Zafeiropoulos F Simon and C PanayiotouldquoA study of the effect of acetylation and propionylation surfacetreatments on natural fibresrdquo Composites A vol 36 no 8 pp1110ndash1118 2005

[12] S Paciornik and M H P Maurıcio ldquoDigital imagingrdquo in ASMHandbook Metallography and Microstructures G F V VoortEd pp 368ndash402 ASM International Materials Park OhioUSA 2004

[13] M Z Rong M Q Zhang Y Liu G C Yang and H M ZengldquoThe effect of fiber treatment on the mechanical properties ofunidirectional sisal-reinforced epoxy compositesrdquo CompositesScience and Technology vol 61 no 10 pp 1437ndash1447 2001

[14] D M R Georget P Cairns A C Smith and K W WaldronldquoCrystallinity of lyophilised carrot cell wall componentsrdquo Inter-national Journal of Biological Macromolecules vol 26 no 5 pp325ndash331 1999

[15] J F Revola A Dietrich and D A I Goring ldquoEffect of mercer-ization on the crystallite size and crystallinity index in cellulose

from different sourcesrdquo Canadian Journal of Chemistry vol 65no 8 pp 1724ndash1725 1987

[16] J R M drsquoAlmeida A L F S drsquoAlmeida and L H de CarvalholdquoMechanical morphological and structural characteristics ofcaroa (Neoglaziovia variegata) fibresrdquo Polymers and PolymerComposites vol 16 no 9 pp 589ndash595 2008

[17] A Bismarck A K Mohanty I Aranberri-Askargorta et alldquoSurface characterization of natural fibers surface propertiesand thewater up-take behavior ofmodified sisal and coir fibersrdquoGreen Chemistry vol 3 no 2 pp 100ndash107 2001

[18] B Wielage T Lampke G Marx K Nestler and D StarkeldquoThermogravimetric and differential scanning calorimetricanalysis of natural fibres and polypropylenerdquo ThermochimicaActa vol 337 no 1-2 pp 169ndash177 1999

[19] K C M Nair S Thomas and G Groeninckx ldquoThermaland dynamic mechanical analysis of polystyrene compositesreinforced with short sisal fibresrdquo Composites Science andTechnology vol 61 no 16 pp 2519ndash2529 2001

[20] A L F S drsquoAlmeida V Calado D W Barreto and J RM drsquoAlmeida ldquoEffect of surface treatments on the dynamicmechanical behavior of piassava fiber-polyestermatrix compos-itesrdquo Journal of Thermal Analysis and Calorimetry vol 103 no1 pp 179ndash184 2011

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

The Scientific World Journal

Impact Factor 173028 Days Fast Track Peer ReviewAll Subject Areas of ScienceSubmit at httpwwwtswjcom

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

The Scientific World Journal

Impact Factor 173028 Days Fast Track Peer ReviewAll Subject Areas of ScienceSubmit at httpwwwtswjcom

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials