DEVELOPMENT OF HIGH DENSITY POLYETHYLENE/RICE HUSK COMPOSITES

Hieu Nguyen, Thanh Tran and Loan Doana, Thai Nguyen and Long Truongb, Son Do and Thao Voc and Thoi Hod

a Da Nang University of Technology - The University of Danang - Vietnamb Plastics and Rubber Technology Center - Vietnam

c HCM City University of Technology - Vietnamd International Polymer Consultant - USA

Houston, 2011

International Polyolefins Conference 2011

Outline

• Introduction

• Review of natural fibers/polyolefin composite technologies

• Preliminary results of rice husk/HDPE composite

• Conclusions/ Path Forward

Green composites

Competitive price/performance

Environmentally safe (Recycling or incineration at end-of-life with energy recovery)

Renewable resource

Natural fibresSpecific mechanical properties (high strength/low density)

Widely applicable

Low machine wear

Safe working condition (vs. Glass fibre)

Low density

Green composites: Composites of the future

Global Production of WPCGlobal Production of WPC

Global Production of WPC by Countries in 2009 (%)

66.7

13.3

11.3

6.7

2.0

US

China

Europe

Japan

Other

Plastic Information EuropePlastic Information Europe

Global production of WPC: 3.3 Billion lbGlobal production of WPC: 3.3 Billion lb

Market of Wood Plastic Composite in US

0

500

1000

1500

2000

2500

2002 2004 2006 2008 2010 2012 2014

Year

Mill

ion

Do

llar

Source: Freedonia IncSource: Freedonia Inc

Market in US in 2010 about $2 Billion. Annual growth rate of about 20%Market in US in 2010 about $2 Billion. Annual growth rate of about 20%

Natural fibers as fillers for green composites

Availability of major biomass sources in Vietnam in 2006

Natural fibers

RICE HUSKRICE HUSK

Rice’s Statistics

• Rice feeds 50% of world population• World rice production in 2007 :1430 B lb• Rice contains 20wt% of rice husk• Rice husk available in 2007 is 286 B lb• About one pound of rice husk available for

each pound of polyolefin produced world wide!

W (B lb) China (B lb) India (B lb) VN (B lb) US (B lb)

286 82 62 16 4

Estimated Rice Husk Available in 2007

Cost rice husk:-Get it free from rice mill-Cost of rice husk

-Cost of transportation -Plus cost of grinding

How the rice husk is used in Vietnam?

Dumping on the river Burning openly

Mainly using for

daily cooking

Using for daily cooking (Cookstoves)

Polluting the

air, water, land…

Disposal cost

Dumping in rivers

Our Vision of Using Rice Husk in Future

+

Review of Natural Fibers/Polyolefin Composite TechnologyReview of Natural Fibers/Polyolefin Composite Technology

Which polymers should be used as matrices for rice husk composites?

Bio-Polymers

Polyolefins

PET

PU, PSABS, PC

PVC

“Green Peace” Triangle

Polyolefins continue to substitute these polymers

EnvironmentalFriendliness

Components Chemical Wt %

Base resins PP, HDPE 50-80

Natural fibers Wood (100-200 micron 20-50

Compatibilizer MAH -HDPE/MAH -PP 2-4

Processing aid Fatty acid esters, waxes 1-4

Other additives AO, UV, FR, Fungicide, Neutralizer 0.1-0.3

Summary of WPC TechnologiesSummary of WPC Technologies

Optimat Ltd and MERL LtdD Gardener

Optimat Ltd and MERL LtdD Gardener

http://www.umaine.edu/adhesion/gardner/5502002/wpc ext over 3-11-02.pdf http://www.umaine.edu/adhesion/gardner/5502002/wpc ext over 3-11-02.pdf

Flexural Strength of PP + 40wt% Filler

0

10

20

30

40

50

60

70

1

Filler Type

Fle

xura

l S

tren

gth

(M

Pa)

Unfilled

glass

talc

CaCO3

wood

Flexural Modulus of PP + 40wt% Filler

0

5

10

15

20

25

30

35

40

1

Filler TYpe

Fle

xura

l M

od

ulu

s (1

00 M

pa)

Unfilled

glass

talc

CaCO3

wood

Key Mechanical Properties of WPCKey Mechanical Properties of WPC

Reinforcing effectiveness: Glass>Talc>Wood>CaCO3Reinforcing effectiveness: Glass>Talc>Wood>CaCO3

English et al English et al

Fiber Cellulose (%)

Lignin (%) Silica (%)

Rice straw 28-36 12-16 9-14

Rice Husk 38-45 15-22 19

Soft wood 40-45 26-34 <1

Hard wood 38-48 23-30 <1

Composition of Some Selected Natural Fibers

Rice husk has much higher silica and lower lignin content than woods

Potential Advantages of Rice Husk

• Abundant resource of rice husk (286 Blb /year world wide)• Rice husk is agricultural waste product (low cost / help the

environment/reduce dependence on oil )• Rice husk is “greener” than wood• High silica content:

– High mildew and fungi resistance– Better fire retardant than wood/polyolefin composite– Lower water absorption than wood /polyolefin composite

Sample Composition(%)

Flexural Strength(MPa)

Flexural Modulus

(MPa)

Impact Strength(KJ/m2)

A PP/RH (70/30) 26 1600 4

B PP/RH (60/40) 23 1800 2.5

C PP/RH/MAPP (56/40/4) 35 1700 3.5

D PP/RH/POE/MAPP(56/30/10/4)

28 1300 5.0

E PP/RH/POE/MAPP(46/30/20/4)

17 800 15.0

PP Profax SM2400 1300 6.5

PP/Talc SM2400/10% Talc 1800* 3*

Reported Key Mechanical Properties of PP/Rice Husk Composites

PP= Profax SM 240 (d=0.9g/cc, MFR=25g/10min, POE=Engage 8150, MAPP=Licomont AR504A, B, C, D, E: Data from M. Mustapa et al (Simposium Polymer Kebangsaan Ke-V) (2005)* Estimated value

Samples B and D have comparable key mechanical properties with PP+10% Talc

Development of Rice Husk /HDPE CompositeDevelopment of Rice Husk /HDPE Composite

Experimental

Ingredients Weight (%)

Rice husk 38 - 58

HDPE 38 - 58

MAPE 4

Rice husks (RH): Long An province, Vietnam (particle size???).

High density polyethylene (HDPE): Sabic Asia Pacific PTE. LTD, Philippin.

Maleic anhydride-grafted polyethylene Fusabond E226 (MAPE): DuPont.

Songnox 417 (0.15 wt%): Songwon, Korea.

Calcium stearate (0.1 wt%).

Materials:

Experimental

(HDPE +MAPE)

Melt-blending (Brabender)

compression molding

Rice husks

Grinding Drying

Processing

Composite samples

T = 160oC = 10 min = 54 rpm

Tensile test: ASTM D638

Bending test: ASTM D790

Notched impact test: ASTM D256

Water absorption

Results: Tensile strength and modulus

30 40 50 602.6

2.7

2.8

2.9

Ten

sile

Mod

ulus

(G

Pa)

Rice husk content (Wt.%)30 40 50 60

16

18

20

22

24

Ten

sile

str

engt

h (M

Pa)

Rice husk content (Wt.%)

RH content polar RH/ apolar HDPE interfacial area tensile strength .

RH fillers have higher stiffness than the polymer matrices tensile modulus of

the composites with rice husk content.

30 40 50 602.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

Bend

ing m

od

ulu

s (G

Pa

)Rice husk content (Wt.%)

30 40 50 60

10

20

30

40

Ben

ding

str

engt

h (M

Pa)

Rice husk content (Wt.%)

RH content bending strength and then .

Bending modulus of the composites with rice husk content.

Results: Bending strength and modulus

30 40 50 605

6

7

8

9

Imp

act

tou

gh

ness (

KJ/m

2 )

Rice husk content (Wt.%)

Results: notched impact toughness

RH fillers is more brittle than HDPE matrix impact toughness of the

composites decreased as rice husk content increased.

Results: Water absorption

0 100 200 300 4000

1

2

3

4

Wa

ter

ab

so

rptio

n (

wt%

)

Time (h)

58 Wt.% RH composite 48 Wt.% RH composite 38 Wt.% RH composite Commercial WPC (from USA)

RH content water absorption

Water absorption of 38 wt.% RH composite is lower to that of

commercial composite sample for decking application.

Conclusions

RH can improve significantly modulus of pure HDPE and composites.

Impact toughness, tensile and bending strength of the composites decrease much

at high amount of rice husk.

RH/ HDPE composite have comparable key properties with commercial WPC

Successful development of rice husk/polyolefin composites:

Production of low cost composite for construction materials

Generate economic development for the rural areas

Reduction of environmental pollution

Path Forward

• Identify target applications for RH/HDPE• Optimize composite composition/additives to meet

the performances for the applications– Mechanical properties– Processability– Processing stability: discoloration/Mw degradation /Bubble

formation– Durability (water absorption/fire retardant, mildew

resistance, UV stability, etc)

Acknowledgements

2010 International Polyolefin Conference/PMAD for warding a scholarship toThanh Tran

The following companies for providing resins and additives

-The Dow Chemical Company-Dupont Company-Chemtura-BASF-Songwon

2010 International Polyolefin Conference/PMAD for warding a scholarship toThanh Tran

The following companies for providing resins and additives

-The Dow Chemical Company-Dupont Company-Chemtura-BASF-Songwon

for your attention

Merci

Danke

Thank you

Arigato

Cám ơn