Indian Journal of Fibre & Textile Research Vol . 28, June 2003, pp. 22 1 -226

Dyeing of red sandalwood on wool and nylon

M L Gulrajani" & S Bhaumik

Department of Textile Technology, Indian Institute of Technology, New Delhi 1 10 0 1 6, India

and

W Oppermann & G Hardtmann

Institute of Fibre and Textile Chemistry, University of Stuttgart, Pfaffenwaldring 55, 0-70550 Stuttgart, Germany

Received 3 May 2001; revised received and accepted 1 7 June 2002

The use of red sandalwood (Pterocarpus santalinus) extract as a dye for wool and nylon has been explored. The colouring components were extracted with organic as well as aqueous alkaline solution from the sandalwood and the physico-chemical properties of the dried extracts evaluated. The extracted dye was applied on wool and nylon with and without mordants and the fastness of the dyed samples to l ight and washing studied. The l ight fastness of the dyed wool samples improved substantially on mordanting with copper sulphate and ferrous sulphate. The wool and nylon samples dyed and treated with mordants, except copper sulphate, showed good wash fastness

Keywords: Nylon, Pterocarpus santalillus, Red sandalwood, Wool

1 Introduction The natural dyes, especially vegetable colourants,

have aroused considerable i nterest in dyeing of textile due to their perceived ecofriendly nature. During last two decades, natural dyes have witnessed a process of revival l .

The present study has been concentrated on the extraction of the colouring components from the red sandalwood, which has been used in various fields besides colouration of textiles, foodstuffs and paper pulp,

Red sandalwood comprises complex colouring com­pounds (Fig. 1 ). Perkin and Everest2 isolated the colour­ing matter and suggested that there are atleast two col­ouring components in the red sandalwood, viz. Santalin and Deoxysantal in, of which Santalin is the main colour-

OH 0Me HO

o HO

HO OH

OH

ing componene-5. Ravindranath and Seshadri6 and Ar­none et aL. 7 confirmed the presence of three colouring components in Santalin (A, B and C).

2 Materials and Methods 2.1 Extraction of Colouring Matter

The crushed red sandalwood for experiment was ob­tained from Alps Industries Ltd, Ghaziabad, India. The colouring matter was extracted from crushed wood by three different methods: (i) Extract- I : extraction with ethanol (yield 20.6%); (ii) Extract-2: first extracted with carbon tetrachloride to remove low polar substance and then with ethanol (yield 23.5%); and (ii i) Extract-3 : aqueous extraction obtained by treating wood chips with 20% (w/w) sodium hydroxide and precipitating the col­ouring component with 30% hydrochloric acid (yield 20%). All extracts were dried at 50°C under vacuum.

H�M. �?�YYOM. o H �

Santalin-A Santalin-B DeoxysantaJin Fig. 1 - Chemical structures of colouring components

"To whom all the correspondence should be addressed. Phone: 265 1 4033; Fax: 009 1 - 0 1 1 -265 1 4033; E-mail : mlg54@hotmail .com

222 I NDIAN J. FIBRE TEXT. RES., JUNE 2003

2.2 Evaluation of Physico-chemical Properties

The physico-chemical properties like moisture content, pH of 1 % dispersion in water and solubility of these extracts were evaluated fol lowing the standard methods.

2.3 Spectral Analysis

The UV IVIS spectra of extracted dye samples at different pH (0.0 1 % solution in methanol) were recorded on Perkin-Elmer Lambda 2- spectro­photometer.

2.4 Dyeing

Wool and nylon fabrics were scoured with 1 giL non-ionic detergent (Lissapol-D) at 90°C for 60 min, washed with hot and cold water and dried before dyeing. Dyeing was carried out at pH 4 for 60 min in water - methanol mixture (95 : 5 , v/v) of dye extracts, keeping the material-to- l iquor ratio at 1 : 50 in a laboratory shaker. The dyeing was started at 40°C and the temperature was raised to 90°C at a heating rate of 2-2.5°C/min. The dyeing was continued at 90"C for another 60 min. In a l l cases, 5 % shade was dyed. Pre- and post-mordanting was carried out for 60 min at 90°C with fol lowing mordants plus other chemical aux i l iaries by a two-bath, two-stage dyeing process:

• • • • •

• •

•

Alum, 20 % owf (pH 4) Alum, 20% owf + tartaric acid, 5% owf (pH 1 ) Potassium dichromate, 3%owf (pH 7) Ferrous sulphate, 3% owf (pH 7) Ferrous sulphate, 3% owf + tartaric acid, 6% owf (pH 6) Stannous chloride, 3%owf (pH 6) Stannous chloride, 3% owf + tartaric acid, 3% owf + oxal ic acid, 3% owf (pH 1 ) Copper sulphate, 6%owf (pH 5 )

2.5 Evaluation of Fastness Properties

The l ight fastness of the dyed samples was tested according to IS : 2454 - 1 984 and the wash fastness according to DIN-20 l O5-C02.

3 Results and Discussion 3.1 Physico-chemical Properties

The physico-chemical properties of the dye extracts are given in the Table I . The pH of 1 % aqueous dispersion shows its acidic character. Extract-3 is more acidic than others. This is because of the residual acid added during precipitation and formation of more phenolic hydroxyl groups due to the break down of the molecules. Red sandalwood is sparingly soluble in hot water. The extracts I and 2 are completely soluble in methanol while in the case of extract-3 , only 68% of the extracted colouring matter is dissolved in methanol .

3.2 Spectral Analysis

The UV spectra of the extracts (Figs 2-5) show that these dyes have strong absorption in UV region (Am"x. = 288nm). The visible spectra of the extracted dyes (extracts 1 , 2 and 3) at different pH are shown in Figs 3, 4 and 5 respectively. The maximum absorption (Amax)

4) u c 4) .0 ... o (/) �

O.S

0 200 300 Wavelength, nm

Fig.2 - UV spectra of red sandalwood extracts

0.5

Extract 3

pH: 7 m.------r pH: 7.67

pH: 9

o L __ -'--___ --'_-=���;;;;J pH: 10

3� 5� �o Wavelength, nm

Fig.3 - Visible spectra of red sandalwood extract I at different pH

Table 1 - Physico-chemical properties of dye extracts

Property Raw material Extract I Extract 2 Extract 3

Moisture, % 3.96 1 2 1 3 . 1 2 1 3 . 1 9

pH of 1 % aqueous dispersion 6.9 4.76 4.7 2.9

Hot water-soluble fraction, % 1 4 38 45 3 1

Methanol-soluble fraction, % 2 1 1 00 1 00 68

GULRAJANI el ai.: DYEING OF RED SANDALWOOD ON WOOL AND NYLON 223

O.S O.S pH: 4

0 0 u u c c 0 0 � � ... ... 0 0 '" '" � � < pH: 9 <

pH: 10 pH: 10

SSO 750 350 SSO 750 Wavelength, nm Wavelength. nm

Fig.4 - Visible spectra of rcd sandalwood extract 2 at different pH Fig.5 - Visible spectra of red sandalwood extract 3 at different pH

Table 2 - L*. a * and b* values of undyed and dyed fabrics

Mordant Dye extract Pre-mordanting Post-mordanting

No. L* a* b* L * a * b *

Dyed wool fabrics

Alum 35.005 3 1 .895 28. 1 22 3 1 .594 30.726 22. 1 38

Alum + T.A. 35 .46 1 34.942 25.848 29.5 1 5 26.459 1 7.466

Pot. dichromate 22.800 22.493 1 1 .775 22.838 1 5 .292 08.444

Ferrous sulphate 27.0 10 1 3.073 04.254 35.583 23.4 1 2 00. 1 09

Ferrous sulphate + T.A. 1 7 .446 1 1 .834 0 1 .4 1 1 2 1 .649 1 3.964 0 1 . 1 1 3

Stannous chloride 24.552 26.998 1 7.45 1 39.307 30.296 1 6.8 1 9

Stannous chloride + O.A . + T.A. 25.357 28.884 1 6. 1 79 4 1 .87 1 3 1 .079 1 8. 5 1 0

Coppcr sulphate 23.30 1 1 6.96 1 1 2. 1 99 1 9. 148 1 1 .775 04.6 1 7

Alum 2 39.729 29.938 23.706 32.847 29.975 1 8.846

Alum + T.A. 2 38.680 30.700 22. 1 94 3 1 .255 29.570 20.752

Pot. dichromate 2 25. 103 23.542 08. 1 82 1 7 .775 09.942 03.853

Ferrous sulphate + T.A. 2 20. 1 3 1 1 2.675 -01 .760 20.875 1 2.658 0 1 . 1 1 2

Stannus chloride + O.A. + T.A. 2 34.503 26.760 1 3. 1 82 28.493 29. 1 43 1 4.639

Copper sulphate 2 28. 8 1 6 1 7 . 1 66 1 2.730 22.079 1 5.494 08.340

Alum 3 59.5 1 3 1 7 .833 23.493 56.305 20.882 27.499

Alum + T.A. 3 48.967 1 8 .4 1 3 23.708 48.443 28. 1 95 28.277

Pot.dichromate 3 22.365 2 1 .566 1 1 .975 20.679 07.486 06.88 1

Ferrous sulphate + T.A. 3 29.729 1 5.064 00.343 27. 1 75 1 2. 894 0 1 .996

Stannous chloride + O.A .+ T.A. 3 46.623 28.694 1 7. 1 60 4 1 .333 26.448 19.760

Copper sulphate 3 30.786 20. 8 1 6 09.304 29.956 1 3. 883 1 5.8 1 7

Dyed without mordant 4 1 .358 26.542 30.269

Undyed 87.000 -0.423 1 1 .849

Dyed nylon fabrics

Alum 53.076 3 1 .653 32.344 48.456 29.7 10 25.533

Alum + T.A. 57.576 32.64 1 35.905 46.622 3 1 .465 26. 1 07 Pot. dichromate 42.627 22.896 0 1 .862 27.947 1 1 .676 02.973 Ferrous sulphate + T.A. 52.9 1 0 26.947 27.950 38.438 1 6.535 09.580

Stannous chloride + O.A. + T.A. 44.079 32.767 1 5 .3 10 36.944 30.392 1 0.339 Dyed without mordant 58.099 33.384 39.474 Undyed 94.0 1 5 -0.5 1 6 0 1 .780

O.A.- Oxalic acid and T.A.- Tartaric acid

224 I NDIAN 1. FIBRE TEXT. RES. , JUNE 2003

at 504 and 474 nm are almost same for all extracts up to pH 10 in methanol solution. After that at pH 1 1 , the Amax changes to 488 nm and gives one maxima only, the colour of the solution changes (not shown 10 figure). This change may be due to the decomposition of the dye or modification of the dye at this pH.

3.3 Dyeing Studies

The reflectance spectra of the dyed samples were recorded and the L * a * b* values were calculated by

CIELAB ( 1 976) equations and are reported 10 Table 2. The low L * values of the samples dyed without mordant as compared to the L * values of undyed samples show that the dye is substantial ly absorbed by wool and nylon. The sorption of the dye by these fibres may be via hydrogen bonds, van del' Waal ' s forces or hydrophobic interactions.

It can be inferred from the L * a * b* values that on mordanting the hue of the dyed fabrics is changed disti nctly. This change can be attributed to the

Table 3 - Fastness ratings of wool fabrics dyed with different dye - mordant combinations

Mordant Pre-mordanting Post-mordanting Dye

extract No W F

3

3-4

4

4

3-4

S C S W L F W F S C S W L F

1

2

2

2

2

2

2

3

3

3

3

3

3

Without mordant

Alum

Alum+T.A.

Pot.dichromate

Ferrous sulphate + T.A.

Ferrous sulphate

Stannous chloride + T.A. + O.A.

Stannous chloride

Copper sulphate

Alum

Alum+T.A.

Pot.dichromate

Ferrous sulphate + T.A.

Stannous chloride + T.A. + O.A.

Copper sulphate

Alum

Alum + T.A.

Pot.dichromate

Ferrous sulphate + T.A.

Stannous chloride + T.A. + O.A.

Copper sulphate

4 4 1 -2

5 4 1 -2 3

3

4

3

4 4 I

3 - 4 3 -4 3

3-4 3-4 3-4

3-4 3-4 3-4

2 - 3 3 3

3 4 - 5 4

3 2 - 3 3

4-5 4-5 4-5

3-4 3-4 3-4

3 3-4 3-4

5 4 - 4 5-4

4-5 4 3-4

2-3 4 3-4

4 4 4-5

3-4 4 4

4 4-5 4-5

3-4 4 4

4 3-4 3-4

4 4 4

4 2-3

3 3 - 4

3 2 - 3

3-4 4

4-5

1 -2 3

3-4 4-5

3 4

2-3 4

4 3

4

1 3-4

2 4-5

2 4

2 3-4

1 -2 4

4-5

4

4-5

4

4-5

4-5

4-5

4

4-5 4-5

4-5 4-5

4 4

4-5 4-5

4-5 4-5

3-4 3-4

4-5 4

4 4

4 3-4

4 3-4

4-5 4-5

4 4

4-5 4

4 4

4 4

4-5 4-5

W F - Wash fastness; S C - Stain ing on cotton; S W - Staining on wool ; and L F- Light fastness.

Table 4 - Fastness rating of nylon fabrics dyed with different dye-mordant combinations

Mordant Pre-mordanting Post-mordanting

2

1 -2

3-4

3-4

4

2-3

3

4

1 -2

1 -2

4

3-4

3

3-4

I 1 -2

3

2-3

2-3

3-4

Dye

extract No W F S W S N L F W F S W S N L F

Without mordant

Alum

Alum + T.A.

Pot.dichromate

Ferrous Sulphate + T.A.

Stannous chloride + T.A. + O.A.

Copper sulphate

3 4 4

3 4-5 5

2-3 5 5

5 5 5 2

4-5 5 5 1 -2

3 4-5 4-5 I

3 4 - 5 4- 5 1 - 2

3-4

3

5

4-5

3

3

W F - Wash fastness; S W - Staining on wool; S N - Staining on nylon; and L F- Light fastness.

4-5 5

4 - 5 4-5

5 4-5

5 5

4 4

4 4-5

I

1 -2

GULRAJANI et al. : DYEING OF RED SANDALWOOD ON WOOL AND NYLON 225

formation of metal-complex between dye, metal ions and fibres. It is further observed that the post­mordanting gives slightly deeper colour as compared to pre-mordanted dyed samples, irrespective of the appl ied dye extract.

Mordants l ike alum, alum + tartaric acid mixture, stannous chloride, and stannous chloride + tartaric acid + oxal ic acid mixture give l ight colour with more yellowish to reddish tone, whereas ferrous sulphate, and ferrous sulphate + tartaric acid mixture give deep colour with violet to moderate reddish tone. Mordanting with potassium dichromate gives deep colour with brown tone, and copper sulphate too gives deep colour with yel lowish tone.

Furthermore, the dye extracts obtained by different extraction procedures gi ve different shades on wool and nylon. This may be because of the different proportions of the colouring components present in these extracts.

3.4 Light Fastness

The l ight fastness rating of the wool and nylon samples dyed with the various dye extracts are given in the Tables 3 and 4 respectively. A comparison between the l ight fastness of dyed wool and nylon shows that some of the wool samples show a l ight fastness in the range of 3-4, but all nylon samples show a very low l ight fastness ( 1 or 1 -2) . It is apparent from the tables that all the un-mordanted samples and the samples mordanted with alum as wel l as alum + tartaric acid show a low light fastness of 1 -2, whi le most of the dyed wool samples mordanted with ferrous sulphate show a l ight fastness of 3-4. Furthermore, the l ight fastness rati ng of wool dyed with extracts 1 and 2 is good with some mordants, w� ile the samples dyed with extract 3 show comparatively low l ight fastness. May be the extract 3 has a higher fugitive colouring component. Moreover, it is observed from TLC that the colouring components of extract 3 are different from those of the other extracts.

Copper sulphate gives the best fastness fol lowed by ferrous sulphate, in both the dyeing methods, on wool with dye extracts l and 2. Potassium dichromate gives good results for extract 2, particularly in post­mordanting method of dyeing.

Since the dye has strong absorption at 287.6 nm, it increases the susceptibi l ity of the dye towards UV fading. Hence, the poor l ight fastness with some

mordants on wool and with all mordants on nylon may be attributed to the l ight-induced change in quinone structure of the dye. Comparatively higher light fastness of some dyed - mordanted wool samples may be attributed to the formation of dye-metal and dye-metal-fibre complexes .

3.5 Wash Fastness

The wash fastness rating of dyed wool and nylon samples is also reported in Tables 3 and 4 respectively. There i s not much difference in the fastness ratings of pre-mordanted and post-mordanted samples. Mordanting with copper sulphate gives poor fastness. Alum gives better fastness than alum + tartaric acid mixture. Ferrous sulphate + tartaric acid mixture performs better than only ferrous sulphate, whereas potassium dichromate gives moderate results. In case of stannous chloride + tartaric acid + oxal ic acid mixture, the reddish tone decreases sl ightly and becomes brown on washing. Dyeing without mordanting does not give acceptable results. The low wash fastness as well as the change in colour on washing can be attributed to the breaking of the dye­mordant complex during washing, resulting into the presence of complex and free dye in different proportions.

4 Conclusions

4.1 It is possible to extract the colouring matter from the wood with organic as well as aqueous alkal i medium. All the extracts give the same absorption maxima up to pH 1 0 in the methanol solution.

4.2 The dye extracts can be appl ied directly on wool and nylon as well as with different mordants. The colour tone changes with different metal ions in both wool and nylon.

4.3 The l ight fastness of wool and nylon samples dyed with sandalwood extract is poor than that of those dyed with Synthetic dyes. It is good with some mordants l i ke copper sulphate, ferrous sulphate and potassium dichromate (post-mordanting) but poor with alum and alum + tartaric acid. Dyeings with extracts 1 and 2 on wool give more or less same results while dyeing with extract 3 gives in general poor fastness properties. In the case of nylon, the l ight fastness is very poor.

4.4 Wash fastness of all the samples dyed and treated with mordants, except copper sulphate, is good for both wool and nylon.

226 INDIAN J. FIBRE TEXT. RES., JUNE 2003

References I Gulrajani M L & Gupta 0, Natural Dyes and their

Application to Textiles (Department of Textile Technology, Indian Institute of Technology, Delhi), 1 992.

2 Perkin A G & Everest A E. Natural Orgal1.ic Colourillg Matters (Longmans Green and Co., London), 1 9 1 8 .

3 Mayer F & Cook A H, Chemistry of Colouring Matters, 3rd edn (Reinhold Publ ishing, New York), 1 943.

4 Uber einen von Perkin als Desoxysantalin. bezeichllelen FarbstoJf aus dem Sandelholz, Ph.D.thesis,Universitat Frankfurt, 1 93 1 .

5 Schweppe H, Handbuch der NaturfarbstoJfe (Ecomed Verlagsgesellschaft), 1 993.

6 Ravindranath B & Seshadri T R, Phytochemistry, 1 2 ( I I ) ( 1 973) 278 1 .

7 Arnone A et al., J Chem Soc, Parkin TrailS. 2 ( 1 975) 1 86.