Indian Journal of Fibre & Textile ResearchVol. 22, June 1997, pp . .124-129

Effect of crosslinking in presence of PEG 600 on dyeability of cotton

D P Chattopadhyay, J K Sharma & A K Parra"The Technological Institute of Textile & Sciences, Bhiwani 125021, India

Received 1 January 1996; revised received 22 October 1996; accepted 10 December 1996

The dyeability and strength properties of cotton fabric resin fmished using Finish KVSI (aDMDHEU based cross linker with built-in-catalyst) in presence of polyethylene glycol 600 (PEG 600)have been studied. The treated samples were dyed with three different vinylsulphone reactive dyes. Thedyeing was evaluated by K/S values and fastness ratings while the strength properties were observed interms of tensile and tear strengths. It has been observed that the dyeability of the crosslinked (resin-finished) fabric substantially increases in presence of PEG 600. The best results are obtained at the op-timum resin cone. of 100 gpl, PEG 600 cone. of 140 gpl, curing temperature of 160°C and curing periodof3 min.

Keywords: Cotton, Cross linking, Dyeability, Polyethylene glycol, Wrinkle recovery

1 IntroductionCotton, despite all its benign attributes for ap-

parel use, has a relatively poor rating during actualwear. This is due to its proneness or tendency toform wrinkles under slight crushing and their re-tention for a long.time'. Crosslinking of cellulosemacromolecules by certain chemicals has thusbeen found to be a suitable antidote to this prob-lem. This technique of imparting crease recoveryproperty to the substrate is popularly known asresin finishing.

The traditional route for finishing cotton fabricis to apply the chemical finish only after the fabrichas been dyed. But, with the passage of time, dye-ing in the garment form has become an importantand growing segment of the textile industry. Theavailability of dyeable easy-care cotton garmentswould permit quick response to fill orders foritems as they are sold without the need for largestock inventories. It would only be necessary toproduce the garments in the undyed state and thendye in specific colours and shades as per the ordersreceived'. So, contrary to the usual process se-quence, the fabric is to be first finished and thendyed. This makes production of dyeablecrosslinked (resin finished) cotton a potential fieldfor research.

Cellulosic fabrics that have been finished foreasy care properties by conventional processingare resistant to dyeing", The changes in dyeability

"Present address: Indo Texprint, Faridabad 121 006, India

because of the crosslinking treatment of cottoncellulose have been shown by Gagliardi andNuessle3

. They found that cotton becomes moreresistant to dyeing as the level of crosslinking in-creases. This property is called "dye immuniza-tion". However, to improve the dyeability ofcrosslinked cotton, techniques like post-mercerization, moist-curing, steam-curing, pad-wetbatch technique, partial hydrolysis of crosslinkedcotton, use of reactive additives, etc have been

d4-10suggeste .

The present investigation was aimed at studyingthe effect of crosslinking in presence of PEG600-a swelling agent~n the colour value,crease recovery and strength properties of the fin-ished-dyed cotton fabric. Parameters like concen-tration of chemicals and curing temperature werevaried to observe the effect discretely.

2 Materials and Methods2.1 Materials2.1.1 Fabric

Desized, scoured, bleached and mercerizedcotton fabric with the following specifications wasused: Yam count, 40s x 40s; reedslin., 88; andpickslin., 84.

2.1.2 Dyes

The following vinylsulphone reactive dyes, ob-tained from Mis Jaysynth Dyechem Ltd, were usedwithout purification: Reactofix Supra YellowHGRL (C.I. Reactive Yellow 15); Reactofix Supra

CHA rrOPADHY AY et al.: DYEABILITY OF COrrON

Red HRBL (C.!, Reactive Red 198A); and Reac-tofix Supra Navy Blue HRL (C.I. Reactive Blue89).

2.1.3 ChemicalsFinish KVSI (DMDHEU with built-in catalyst),

Ceranine UN liquid (non-ionic softener), SandozinNISI liquid (non-ionic wetting agent), all obtainedfrom MIs Sandoz (India) Ltd, and polyethyleneglycol 600 (swelling agent) ofLR grade were usedfor finishing treatment of fabric. Glacial aceticacid of LR grade was used for adjusting pH of thefinish bath. Indogen-CS, a non-ionic detergentsupplied by MIs Indokem Ltd, was used for soap-ing, while sodium silicate (132°Tw), sodium hy-droxide and urea, all of LR grade, were used fordyeing.

2.2 Methods2.2.1 Fabric Preparation

The bleached and mercerized fabric was thor-oughly washed, neutralized and dried at room tem-perature.

2.2.2 Fabric TreatmentThe fabric samples were treated with different

concentrations of Finish KVSI and then dyed withdifferent reactive dyes (vinylsulphone type) sepa-rately. The effect on dyeing was observed bytreating with selected concentration of FinishKVSI and different concentrations of PEG 600followed by reactive dyeing. The effect of curingtemperature with selected concentration of FinishKVSI & PEG 600 was studied and the effect ofPEG 600 at different resin concentrations was alsoprobed into.

In all the above cases, the fabric was paddedwith the finish solution in a two-bowl laboratorypadding mangle by one dip-one nip process at 70%(approximate) expression. The padded fabric wasthen mounted on a pin frame, dried at 60°C for 5min and cured at 160°C for 3 min in an air circula-tory type laboratory oven. The cured fabric wasthoroughly washed, dried and then padded with 10gpl vinylsulphone dye solution (containing requi-site chemicals) in the same padding mangle with-out making any change in the expression. Thispadded fabric was then batched at room tempera-ture for 24 h in a closed polyethylene cover. Afterthe batching time was over, the batching samplewas unrolled, rinsed thoroughly with cold runningwater and then with 'hot water, soaped, washed and

125

dried.After optimizing the recipe, the effect of curing

temperature was studied by carrying out curing at130, 145, 160 and 175°C keeping the curing timeconstant (3 min).

2.2.3 Measurement of Tensile StrengthThe tensile strength of the fabric samples was

measured in a pendulum strength tester at constantrate of traverse. The strength of fabric was taken asaverage strength of warp plus weft and expressedin terms of percentage retention of the original.

2.2.4 Measurement of Tear StrengthThe tear strength was measured by single rip

ballistic test on Elmendorf tearing tester. Thestrength was taken as average strength in warp plusweft direction and expressed in terms of percent-age retention of the original.

2.2.5 Evaluation of Colour StrengthColour strength of the samples, expressed as KlS

value, was evaluated using the following equation:2

K / S = (l-R)R

where R is the reflectance; and K and S, theKubelka-Munk absorption and scattering coeffi-cients respectively. All the measurements wereperformed in the Macbeth 2020+ computer-aidedcolour matching system.

2.2.6 Assessment of Fastness PropertiesStandard ISO-II test was followed for the meas-

urement of wash fastness grades. SDL-237 lightfastness tester containing MBTL fading lamp wasused to test the light fastness of the dyed fabricsamples.

3 Results and Discussion3.1 Effect of Resin Pretreatment

Although it is known that crosslinked cotton haspoor dyeability, the Finish KVSI-treated fabric wasdyed separately with all the three vinylsulphonedyes. This was done with a view to know the ex-tent of dyeability of such finished fabric and tojudge the improvement in dyeability when pre-treated with additives.

Table I shows that WRA increases by the appli-cation of resin, as expected, and it further increaseswith the increase in resin concentration. The KlSvalue sharply decreases on crosslinking and withthe increase in resin concentration, it further de-

126 INDIAN J. FIBRE TEXT. RES., JUNE 1997

0creases. The tensile and tear strengths obviously

~~ 0""''''''<'1<'"1 decrease on increasing the concentration of the~ o.....:.....:oo-q:0 ;i:I:: -t'-['-\O\O finishing agent. The overall finishing effect is quite

~ s::0 good at a concentration of 100 gpl of Finish KVSI.:I:: .~

0 "O.....l::s ~ 0\0\00\00s o~ Ooovio\ 3.2 Effect of PEG in Resin Bath>. -5 P:::I:: •....•00001'\0> 3.2.1 Wrinkle Recovery Angle'" s::Z ~ The presence of PEG 600 in the resin bath,"0 en!a

~~~ 0"<1""<1""<1"\0 however, does not affect the wrinkle recovery an-.....l =d Or'..oMO gle (WRA) much. The reduced level of crosslink-

~ >:I:: •....•I' I' I' I'

:I:: ing that might have occurred is mitigated by the"0 presence of four potential reactive sites in the0P::~

0 DMDHEU-based resin and by the potential of hy-~~ 00\<'"1<'"1<'"1 drogen bonding between the ether sites in theo Ocx:icx:iocx:i

:I:: ~ ;i:I:: •....•\0\0\0.,...PEG!!. Table 2 shows that there is a very small~ s:: decrease in WRA with increase in PEG 600 con-.2 0., ".gcentration. This may be due to the reaction of a>- 0

-5 ~ part of the polyfunctional crosslinker with glycol,.~ -5 .....lthereby inhibiting, to some extent, the reaction of"0

~~~

o V') V') •..•.•V)0 OOOr'N>. P:::I:: -r-£-\O\O the crosslinker with the cellulose hydroxyl groups."0

"0 ~ In other words, the competition of polyol with the!a 'ViCi5 s:: cellulose hydroxyl for the crosslinking agent may0> f- be responsible for decrease in WRA!2.~ ~~ 0.,... •....••....•0\..r:: It is also expected that the swelling of cottonen =d ON..oviN·s >:I:: •....•1'\0\0\0

~ due to PEG 600 exposes the -OH groups of cellu--5 0 lose for crosslinking but at the same time, -OH.~

~~ ~"<1""""""'0"0

<'"I •... groups present in the swelling agent itself compete0 ;i:I:: •....•"<1""<1"<'"1<'"11ii with the cellulose -OH groups for crosslinking.0bu Thus, as far as WRA of the treated fabric is con-.;::.0 .....l cerned, the reaction of the polyol with crosslinker<L:!

~ ~~ f"'I"1ot-V')-s:: o\MNNN ..!:i has a negative effect while the same swelling agent0 ~::I:t:: !a can have a positive effect by enhancing the acces-0u i!'.... sibility of crosslinker to the cellulose hydroxyl0 0>en

~~0 groups. Thus, the predominance of one of these0.€ """":<'101'''''' u0

0 =d o .... •..effects over the other is likely to set the trend of0.. >:I:: •....•("'f)("f")NN 0

0 ~•.. change in WRA.0.. s::.;::s::

~0s:: 0 3.2.2 Dyeability0 ..2.....l

.~ <'10000\.,...

jr:IlP:: "<1"0\--<'1 It is evident from Table 2 that incorporation ofb i::I: .....•-NNNs:: PEG 600 in the finish bath substantially increases0os:: E the dye depth of cotton when subsequently dyed0u 0s:: 0

~ with vinylsulphone dyes. This trend is observed for'Vi "0 .....l

~~<'10\["-.,...0

0~~"

"<1"0\0-<'1 0 all the three dyes used. Again, on increasing the•..b.... P::::I: .....•-NNN

0 concentration of swelling agent (PEG 600), theu~ colour strength of the post-dyed samples increases.U.l

However, beyond a particular concentration ofI ~~•....• <'"1"<1"00<'"1\0PEG 600 (140 gpl), the colour strength tends to=d .q-O\o--

0 >::I: --NNN

~ decrease. At concentrations below 140 gpl, thef-lower KlS values observed could be due to less

" swelling of fibre while at high concentration (160"0c U b~ gpl) the predominance of crosslinker over the'Vi c- §oooo0 8 5li uOO 0 <'I "<1" swelling agent could be the reason for deteriora-P:: [fl

Tabl

e2-

Effe

ctof

PEG

600

conc

entra

tion

onpr

oper

ties

ofco

tton

fabr

ictre

ated

with

Fini

shK

VSI

and

PEG

-600

and

dyed

with

Yel

low

HG

RL,

Red

HR

BL

and

Nav

yB

lue

HR

L

PEG

WR

A,

deg

KlS

Tens

ilest

reng

thre

tent

ion,

%Te

arst

reng

thre

tent

ion,

%co

ne.

Yel

low

Red

N.

Blu

eY

ello

wR

edN

.B

lue

Yel

low

Red

N-,B

lue

Yel

low

Red

N.

Blu

egp

lH

GR

LH

RB

LH

RL

HG

RL

HR

BL

HR

LH

GR

LH

RB

LH

RL

HG

RL

HR

BL

HR

L

Con

trol"

143

142

142

10.1

10.3

13.6

100

100

100

100

100

100

020

820

721

03.

02.

74.

166

.167

.263

.376

.278

.469

.110

020

620

721

06.

25.

04.

171

.367

.864

.280

.082

.172

.712

020

319

920

86.

25.

88.

473

.271

.065

.979

.379

.673

.5

140

203

195

200

7.2

6.5

9.2

71.8

70.1

67.3

78.4

79.6

71.2

160

196

195

194

6.7

5.7

8.6

72.4

69.0

68.1

79.1

80.8

71.5

"Sam

ple

with

out

any

finis

hing

treat

men

t.

Tabl

e3-

Effe

ctof

curin

gte

mpe

ratu

reon

prop

ertie

sof

cotto

nfa

bric

treat

edw

ithFi

nish

KV

SIan

dPE

G60

0an

ddy

edw

ithY

ello

wH

GR

L,R

edH

RB

Lan

dN

avy

Blu

eH

RL

[Con

e.of

Fini

shK

VSI

,10

0gp

l;C

one.

ofPE

G60

0,14

0gp

l;an

dD

urat

ion

ofcu

ring,

3m

in]

Cur

ing

WR

A,d

egKlS

Tens

ilest

reng

thre

tent

ion,

%Te

arst

reng

thre

tent

ion,

%te

mp.

Yel

low

Red

HR

BL

N.

Blu

eY

ello

wR

edH

RB

LN

.B

lue

Yel

low

Red

HR

BL

N.

Blu

eY

ello

wR

edH

RB

LN

.B

lue

°cH

GR

LH

RL

HG

RL

HR

LH

GR

LH

RL

HG

RL

HR

L

130

180

175

184

8.1

8.0

10.5

78.2

77.1

74.8

85.8

84.5

79.9

145

192

187

189

7.9

7.6

10.0

74.7

73.0

70.3

80.1

82.7

76.6

160

203

195

200

7.2

6.5

9.2

71.8

70.1

67.3

78.4

79.6

71.2

175

206

200

209

6.1

5.1

7.0

62.2

63.2

58.5

69.4

69.4

60.3

Tabl

e4-

Effe

ctof

resi

nco

ncen

tratio

non

prop

ertie

sof

cotto

nfa

bric

treat

edw

ithFi

nish

KV

SIan

dPE

G60

0an

ddy

edw

ithY

ello

wH

GR

L,R

edH

RB

Lan

dN

avy

Blu

eH

RL

[Con

e.of

PEG

600,

140

gpl]

KlS

Tens

ilest

reng

thre

tent

ion,

%R

edH

RB

LN

.B

lue

Yel

low

Red

HR

BL

N.

Blu

eH

RL

HG

RL

HR

L

Res

inco

ne.

gpl

WR

A,d

egTe

arst

reng

thre

tent

ion,

%Y

ello

wH

GR

LR

edH

RB

LN

.B

lue

HR

LY

ello

wH

GR

LY

ello

wR

edH

RB

LN

.B

lue

HG

RL

HR

L

80 100

120

140

197

200

200

211

76.1

71.2

69.4

64.8

7.0

7.2

7.3

7.6

8.7

9.0

9.5

9.6

75.1

71.8

65.9

63.0

70.5

70.1

66.6

60.3

69.1

67.3

62.0

59.9

192

203

210

214

189

195

205

208

6.4

6.5

6.8

6.8

80.9

78.4

75.1

70.7

84.4

79.6

75.9

69.3

9 > ~ ~ -< > -< ~ f:.. o ~'tIl F ~ ~ ~ •... N --.

J

128 INDIAN J. FIBRE TEXT. RES., JUNE 1997

tion in dye depth. Moreover, it is also felt that theextent of complex formation by reaction betweenpolyol and crosslinker could be a determiningfactor in setting the trends of WRA and KlS.

3.2.3 Tensile and Tear StrengthsThe fabrics finished in presence of PEG 600

show slightly improved tensile and tear strengths.The reason could be attributed to less stiffening ofthe substrate as the number of crosslinks is slightlyless due to the presence of glycol. The minor im-provement in strength properties is, however,achieved at the expense of wrinkle recovery. But,no specific trend in strength loss is observed onincreasing the concentration of PEG 600.

3.3 Effect of Curing TemperatureTable 3 shows that, in general, the results ob-

tained at a curing temperature of 160°C are rea-sonably good. At 130°C and 145°C, the WRA val-ues are less due to the inadequate crosslinking ofthe resin. The strength properties are, however,superior at lower curing temperature but at hightemperature (175°C) the strength loss is quite high.WRA is maximum at 175°C in all the cases. The

KlS value decreases on increasing the curing tem-perature. This may be due to better crosslinking ofresin with cellulose on increasing the curing tem-perature. Consequently, less -OR groups in cellu-lose are left for taking up the dye. Among the PEGand DMDREU-treated cottons, moisture regainand water of imbibition are highest for those curedat relatively lower temperature \3. This obviouslycontributes to high KlS values for the samplescured at 130°C and 145°C.

3.4 Effect of PEG 600 at Different Resin ConcentrationsIt is observed from Table 4 that WRA increases

with the increase in resin concentration from 80gpl to 140 gpl. Quite interestingly, the increase inresin concentration is accompanied by a nominalincrease in KlS value also. This could be due to thelocking mechanism of the resin, thus retaining thedye in substrate. Moreover, there is a decrease inboth tensile and tear strength retentions with in-crease in resin concentration.

3.5 Fastness PropertiesGood fastness to washing and light was ob-

served in almost all the samples (Tables 5-8).

Table 5-Effect of resin concentration on fastness properties of cotton fabric dyed withYellow HGRL, Red HRBL and Navy Blue HRL after crosslinking

Resin Wash fastness Light fastnesscone, Yellow Red N. Blue Yellow Red N. Bluegpl HGRL HRBL HRL HGRL HRBL HRL

Control" 4-5 4-5 4 6 5 680 4 4 4 6 5 6100 4 4 4 6 5 6120 3 4 4 6 5 6140 3 4 3 5 5 5

"Sample ~i~hout any finishing treatment.

Table 6-Effect of PEG 600 concentration in the resin bath on the fastness properties ofcotton fabric dyed with Yellow HGRL, Red HRBL and Navy Blue HRL after

crosslinking

PEG Wash fastness Light fastnessconc. Yellow Red N. Blue Yellow Red N. Bluegpl HGRL HRBL HRL HGRL HRBL HRL

Control" 4-5 4-5 4 6 5 60 4 4 4 6 5 6100 4 4 4 6 5 6120 4 4 4 6 5 6140 3-4 3 4 6 5 6160 4 3 3-4 5 5 6

"Sample without any finishing treatment

CHA TIOPADHY AY et al.: DYEABILITY OF CaTION 129

Table 7-Effect of curing temperature on the fastness properties of cotton fabric dyedwith Yellow HGRL, Red HRBL and Navy Blue HRL after crosslinking

[Cone, of Finish KYSI, 100 gpl; and Cone, of PEG 600, 140 gpl]

Curing Wash fastness Light fastnesstemp. Yellow Red N. Blue Yellow Red N. Blue°c HGRL HRBL HRL HGRL HRBL HRL

130 4 4 4 6 5 6145 4 4 4 6 5 6160 3 3 3 6 5 6175 2-3 3 2 5 5 5

Table 8-Effect of resin concentration in presence of PEG 600 on the fastness proper-ties of cotton fabric dyed with Yellow HGRL, Red HRBL and Navy Blue HRL after

crosslinking

[Cone, of PEG 600, 140 gpl]

Resin Wash fastness Light fastnesscone. Yellow Red N. Blue Yellow Red N. Bluegpl HGRL HRBL HRL HGRL HRBL HRL

80 4 4 4 6 5 6100 3 3 3-4 6 5 6120 3 3 3 6 5 6140 3 3 3 6 5 6

4 Conclusions

Dyeability of resin (Finish KVSI)-treated cottonfabric with vinylsulphone reactive dyes can be en-hanced to a great extent by incorporating PEG 600(a high boiling point swelling agent) in the resinbath. Among the concentrations of the additivestudied, 140 gpl of PEG 600 gives the best dye-ability results. To obtain reasonably balancedproperties, the acceptable resin concentration is100 gpl in presence of PEG 600. A curing tempera-ture of 160°C and a curing period of 3 min givereasonably good results.

AcknowledgementThe authors are grateful to Prof ReD Kaushik,

Director, The Technological Institute of Textileand Sciences, Bhiwani, for help and encourage-ment during this work.

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A, J Appl Polym Set, 27(3) (1982) 871.5 Prett K, Me/liand Textilber, 46 (1965) 73.6 Pierce A G (Jr) & Frick J C (Jr), Am Dyest Rep; 57 (1968)

864.7 Pareikh D Y, Frick J G (Jr) & Reid J 0, Am Dyest Rep,

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