ECONOMICAL DYEING OF POLYESTER /COTTON BLENDS WITH MULTIFUNCTIONAL PROPERTY BY USING CYCLODEXTRINS

ECONOMICAL DYEING OF POLYESTER /COTTON

BLENDS

WITH MULTIFUNCTIONAL PROPERTY BY USING

CYCLODEXTRINS

ABSTRACT

The present work illustrates the beneficial effects of applying a hybrid approach

which includes the treating of P/C blended material with pure PEG (M.wt.400), PEG

solution containing small concentration of NaOH and third one is treatment with CD after

the later method. To realise this approach, P/C blended samples were padded in the above

mentioned chemicals to wet pick up of 100% (o.w.f), and dried then subjected to

saturated steam curing in the appropriate manner. Then the dyeing is performed using

HTHP technique. The dyeing liquor was prepared using Dispersing agent, dye solution

etc.The pH of the bath was maintained at 5.5 using acetic acid. Well wetted fabric was

entered in to the dye vessel and the dyeing is performed for the prescribed time under

definite temperature. Finally, the dyed samples were thoroughly soaped with non-ionic

detergent (3 g/l of lissapol N), rinsed and dried (for the dark shades R/C treatment was

given by using caustic and hydros each 1 g/l at 70 ºC).

PEG & CD can be effectively used to dye P/C blends using disperse dyes only.

So that it can conserve time, energy, man power etc. Nevertheless, CD plays in the

following roles 1) To substitute surfactants in P/C processing; 2) When bound chemically

with fibres, it provides hydrophilicity 3) To perform easy removal of sweat and sweat

degradation products from the textiles.

The successful application of disperse dyes on P/C Blend with the help of PEG

& CD bring out numerous advantages such as a) Dyeing of P/C in a single stage process

by using Disperse dyes only b)Saving of water, energy, time( due to single stage process)

c)Replacing of conventional surfactants & thickeners by CD (It will give low BOD &

COD Value than conventional one) d)Enhancement of functional property of the P/C

fabric by means of CD e)Minimizing of the effluent problem due to shortening

processes, re-placing of surfactants etc f)An economical process etc

LIST OF SYMBOLS, ABBREVIATIONS or NOMENCLATURE

SYMBOLS,

ABBREVIATIONS

or

NOMENCLATURE

EXPLANATION

app Approximately

BIS Bureau of Indian Standards

BOD Biological Oxygen Demand

CCM Computer Colour Matching

β-CD Cyclodextrins

COD β-Chemical Oxygen Demand

g/l Grammes Per Liter

M.wt Molecular Weight

MR Moisture Regain

NaOH Sodium Hydroxide

o.w.f On Weight of the Fabric

P/C Polyester Cotton

PEG Polyethylene Glycol

pH A measure of Acidity or Alkalinity

R/C Reduction Clearing

SHPI Sodium hypophosphite

W/W Weight / Weight

CHAPTER 1

INTRODUCTION

The Multifunctional Auxiliaries and Energy Conservation processes are the

Prime concern of the Textile Chemical processing industry. Attempts to utilize CD in

textile applications started in the late 1980s.This was brought about by the recognition

that the inclusion complex formation capability of CD can be applied to the deodorant ,

aroma, antimicrobial finishes that have recently popular and in treating effluents. Since

then research and development of CD applications have become active, and the

possibilities of using CD in textile finishing are being explored recently in the textile

industry .With the trend in the textile industry demanding high quality and new

properties, the range of application of CD is expected in P/C blends dyeing. In this study,

for the coloration of P/C blend fabrics, so-called disperse dyes are used, which are very

poorly soluble in water(0.1-10 mg/L).Without using solubility-enhancing

agents(surfactants),uniform dyeing is not possible. CD however can replace the

surfactant, and their COD in the waste water is lower than that of the usual textile

surfactants 16.

With the scarcity as well as increasing prices of fuel, it has become one of

the imperative duties of the present day researchers to cut-short the processes, without

sacrificing the desirable properties of the product for economy in general and

conservation of energy in particular. To meet the above objectiveness ,in the dyeing of

P/C blends use of high boiling swelling agent like PEG can be used. In conventional

process P/C dyeing involves various steps, viz. PET dyeing, reduction clearing, washing,

drying; followed by cotton dyeing, washing, drying .If unfixed dyes is not removed

properly during soaping/washing treatment will lead to poor fastness properties of the

dyed material .Thus ,sever washing-off treatments ,reduction clearing and intermediate

dyeing steps are involved in two bath P/C dyeing, which leads to more consumption of

time, man-power ,energy and also declination in the productivity. In this study to

conserve time and energy, it is desirable to develop an economical process which can dye

both the portions of the blend without altering their viz _ properties. Therefore in the

present investigation, an attempt can be made to dye P/C blends in a single bath with

disperse dyes using high boiling swelling agent (PEG)

Normal dyeing of P/C blends involves the elaborated process by using

appropriated class of dyes for PET and Cotton portion. The proposed work aims to use

Cyclodextrin (CD) and poly ethylene glycol(PEG) as a Pre-treatment to dye both

polyester and cotton portion by only disperse dyes in the single stage process.

Nevertheless, CD can cause some Multi functional property on the dyed fabric like

hydrohilicity, anti soiling etc and the generation of COD and BOD also will be low

compare with sodium alginate in the conventional process 31 And use of high boiling

swelling agent like PEG is desirable in P/C dyeing to develop an economical process

which can dye both the portions of the blend in a single stage with disperse dyes so that

it can conserve time, energy, man power etc1, 34.As on today commercially, the blends of

P/C are successively dyed by two bath process using disperse dyes and cellulosic dyes

respectively. Even though one bath processes have been tried using various combinations

of cellulosic dyes along with disperse dyes, none of the processes were not successful and

are not practical commercially.

The successful application of disperse dyes on P/C Blend with the help of PEG &

CD bring out numerous advantages such as a) Dyeing of P/C Blend in a single stage

Process by using Disperse dyes only b)Saving of water, energy, time( due to single stage

process) c)Replacing of conventional surfactants & thickeners by CD (It will give low

BOD & COD Value than Conventional one) d)Enhancement of functional property of the

P/C fabric by means of CD e)Minimizing of the effluent problem due to shortening

processes, re-placing of more polluting surfactants etc f) An Economical process

etc.Poly-ethylene Glycol (PEG) & Cyclodextrin (CD) can be effectively used to dye P/C

blends using disperse dyes only. Which can alter the nature of polyester & cellulosic

fibres contained in the P/C Blends and making it viable to dye cellulosic fibre with

disperse dyes along with hydrophobic PET.

CHAPTER 2

LITERATURE OF REVIEW

2.1 POLYESTER

Polyester fibres are widely used in the textile field, owing to its outstanding

characteristics, i.e., high strength, high melting point, better crease resistance, high elastic

modulus, better creep properties high wear resistance, better dimensional properties and

stable for blending with other type of fibres. However, the fibres have low moisture

absorption, high static built-up, high pilling tendency and are difficult to dye under

practical conditions due to its compact physical structure and absence of chemical active

groups etc. Extensive research has been carried out on the modification of the polymer

chain to overcome some of the inherent drawback of the polyester (PET) fibres.

It was reported that PET fibres desirable properties can be prepared (a) by modifying the

chemical structure of the polymer during polymerization and (b) by modifying the fibre

surface and the structure by treating with suitable chemical. In the first method,

incorporating additives during the manufacture can modify the PET fibres. The

modifying compounds may be mono-functional and di-functional or polymeric

compounds 35. At present this type of polyester fibres are well established commercially33.

In the second method surface modification of PET fibres have been achieved using

various methods such as alkaline hydrolysis28graft polymerization of hydrophilic

monomers14, and steaming12

Nevertheless, P/C blend enters in market because it has advantages of both PET

and cellulose. P/C blend has got lot of advantages from user point of view but from dyers

point of view it was difficult to dye the blends. And use of high boiling swelling agent

like PEG is desirable in P/C dyeing to develop an economical process which can dye both

the portions of the blend in a single stage with disperse dyes so that it can conserve time,

energy, man power etc1,34

Three factors are mainly responsible for making PET fiber difficult to dye: (a)

high-fiber crystallinity, (b) a marked hydrophobic character, and (c) an absence of

chemically reactive groups in the polymer. Owing to these factors, PET cannot be dyed

with the same dyes that are generally employed for cellulosic, protein, nylon, or acrylic

fiber. Since the ester groups content of cellulose acetate and polyester fiber is nearly the

same (40-45%), attempts have been made to dye polyester fiber with disperse dyes by the

same method used for cellulose acetate. However, it was observed that PET was not dyed

at 80-100oC. This was due to a very slow rate of diffusion of disperse dyes into the

compact polyester fiber.

In the early years attention was directed to finding a means of improving

dyeability. The yield of a disperse dye on PET is limited and vastly inferior to the yield

on nylon and cellulose acetate because of the low rate of dyeing rather than the low

substantivity of early disperse dyes for PET. The problem is solved by using different

approaches to increase the rate of dyeing.

1. Building up dye molecules inside PET (azoic dyeing).

2. Opening up the fiber structure to bring down the Tg (carrier dyeing).

3. Using temperatures above 100°C [high-temperature (HT) dyeing].

4. Heating the dye and the PET in the dry state together near the softening temperature of

the fiber (thermosol or thermo fixation dyeing).

5. Replacing water with an organic solvent as a dyeing medium (solvent dyeing).

Apart from the above approaches, chemical modification of PET (to impart

affinity for dyes other than nonionic dyes is commercially practiced in order to get

cationic dye able PET. Similarly, the transfer printing process is used to colour polyester

in solid shades.

The use of solvents for dyeing PET is intensively investigated in the early 1970’s.

Even though PET can be dyed to any depth of shade using solvents, none of the solvent

dyeing methods ever reached a state of a commercial feasibility. The azoic dyeing

process was once used to colour PET, but with the development of disperse dyes and

various dyeing methods; it has now lost its importance. It is now used mainly to produce

black shades.

2.2 DYES FOR POLYESTER

PET is now dyed with nonionic dyes specially synthesized to suit the dyeing

processes. Nonionic dyes with low aqueous solubility at dyeing temperatures (100-

130oC) are the best dyes for PET. The solubility of nonionic dyes in water is low such

that these dyes are considered water insoluble. It is essential; however, these dyes should

have some solubility in the dye bath to get dyed in the aqueous bath. These dyes are

applied in the form of an aqueous dispersion. The small aqueous solubility and the

particle size of a disperse dye plays a vital role in the rate of dissolution and the rate of

adsorption of dye by PET. Dispersing agents play a vital role in dyeing process. Some

disperse dyes are sensitive to heavy metals and form chelated compounds with calcium

ions giving tonal variations. Soft water is therefore used for dyeing.

Disperse dyes are available in two forms-micro disperse granules or powder and

liquid dyes. The dispersion of a dye is spray dried to get solid granules and powders. The

amount of dispersing agent required to get stable dispersions can be 40-90 % and usually

60% of the dried disperse dye- powder. This large proportion of a dispersing agent in the

granules and powders of disperse dyes creates problems such as increasing aqueous

solubility, inducing migration during drying of padded goods, lowering the exhaustion of

dye bath and so on. The properties expected of micro disperse -dye granules include

stability, dryness, uniformity, free flowing, non-dusting, and non-hygroscopic nature,

good bulk density (app.0.5 or more), and ready dispersibility. Liquid dyes are dispersions

with a low concentration of a dispersing agent. Dispersion stability, easy miscibility,

proper pH., and free flowing nature are some of the prerequisites for liquid dyes. Since

metering pumps can be used for liquid dyes the additions, weighing and so on not pose

no problems. Liquid dyes are easy to dissolve and to use. They pose none of the problems

that arc associated with the granular dyes. However liquid dyes are likely to dry up to

settle, and to alter in concentration during storage. Special precautions are required to

store and handle liquid dyes. Many times, disperse dyes have poor storage stability,

particularly, if they are exposed to a humid atmosphere. Under these conditions, the

dispersion breaks into lumps. Such a dye is likely to give uneven, specky dyeing. The

state of the dye dispersion can be easily checked by dispersing the dye in water and

dropping it on filter paper. If the dispersion is good, no particle will be visible on the

filter paper. Improvements in the physical form of the dyes improve the final color

results.

Chemically, the disperse dyes come from various classes Such as azo,

anthraquinone. Methine. and diphenylamine. The dyes usually have NO2, CN, OH,

halogen and primary, secondary, and tertiary amines groups but they never have any

polar groups which easily ionize in an aqueous bath. Some of the dyes have a free

COOH group. Such dyes are usually applied by printing techniques under acidic pH so

that this group does not ionize substantially. Free aliphatic hydroxyl groups that impart

high aqueous solubility are esterified with acetic acid or a mixture of acids. These dyes

generally have low molecular weight which facilitates their entry and diffusion into the

highly crystalline polyester fiber. The higher the molecular weight of the dyes, the slower

is the diffusion in the fiber. They have significant, though low vapor pressure.

Particularly at elevated temperatures. Disperse dyes are sensitive to pH. Methine dyes

hydrolyze or dimerize under alkaline conditions. The pH the dyebath for dyeing PET is

therefore maintained on the acid side. A redox buffer is usually also added to the dyebath

to avoid reduction of disperse dyes 25

The fastness properties and dyeing characteristics of disperse dyes are considered

with particular reference to the subsequent treatments. In the case of yam dyeing and. to a

lesser extent, piece dyeing, wet fastness after heat setting is important since the knitting

or coning oils on dyed goods can lead to the migration of the dye into the oil. Besides the

usual light and wash fastness, the sublimation fastness of disperse dyes is very important

since dyes of low sublimation fastness give problems during subsequent treatments such

as resin finishing. A similar high standard of fastness is required for dry and wet rubbing.

Migration of dye to the surface of the fiber during the heat-setting process frequently

results. Dyes with high sublimation fastness are therefore used for the dyeing of yarns.

Similarly, dyes, auxiliaries and dyeing conditions are selected to give optimum coverage

of small variations in dye affinity of textured yarns. Thus; dyes used for yarn dyeing must

meet the following specifications:

1. Good dispersion properties, so that the dye is not filtered on a package of yarn

that constitutes an effective filter. Paste brands of disperse dyes are usually

preferred for yam dyeing.

2. Good stability in HT bath during dyeing (130°C/2 h).

3. Good leveling properties, at least with the addition of a surface-active agent. Use

of certain carriers help in getting level dyeing of a yarn package.

4. Good sublimation fastness.

2.3 MECHANISM OF DYEING

The mechanism of dyeing PET with nonionic dyes under different conditions of

dyeing has some common features and some significant differences. HT dyeing and

carrier dyeing involve dye transfer from aqueous baths, while in thermo fixation dyeing;

the water in the pad liquor is completely expelled by a drying process before the dye is

fixed on PET.

The contribution of the PET structure to the dyeing mechanism remains the same for

the three processes because the fiber does not absorb any significant amount of water and

the presence or absence of water on the fibre does not play any significant role in the

sorption of dye by PET. The dye is adsorbed only in the amorphous regions of PET, that

is, it does not enter the crystalline regions. Thus, if calculated on the basis of the

amorphous content of the PET materials, the fiber saturation values of a dye on different

PET materials are similar (FIG.2.1). The percentage composition of the crystalline and

non-crystalline regions in the fiber may vary from fiber to fiber and the fiber may exhibit

apparent differences in its dyeing behavior.

The penetration of dyes in the PET structure is explained by the free volume theory

for the low-molecular-weight compounds in an amorphous polymer. The energy effects

in dyeing show abrupt changes over a very short range of temperatures at Tg.

FIG.2.1 Temperature dependence of true saturation values of dyes on polyester

material.

(a) Fixed in air oven: O: Fixed in metal press: (b). Saturation values were calculated

for three polyesters on the basis of their amorphous content when the data on all

polyesters lie on the same plot.

The concerted movements of Chain segments of polymer molecules are started at Tg.

An increase temperature of above Tg, raise the frequency and amplitude of the movement

of chain segments. This facilities diffusion of dye and the rate of diffusion increase with

the temperature. In the thermo fixation process, however, as the thermo fixation

temperature increases and approaches the softening temperature of PET, there is sudden

drop in the fiber saturation value (FIG.2.1). This is attributed to the increased

crystallization of PET chains during the pre-melting stage, which lowers the amorphous

content of the fiber 7

Under dyeing conditions, the rate of dye molecules on the fiber surface is always

higher than the rate of diffusion into the fiber. There fore, the former does not exhibit

any influence on the overall rate of dyeing and the diffusion of dyes within the fiber is the

rate determining step. Disperse dye has a tendency to deposit on the fiber surface. In the

course of dyeing, this deposited dye has to be desorbed to migrate to some other part of

the fiber material to get the level uniform dyeing 22. This prolongs the dyeing process.

Significant surface deposition takes place only from over saturated dye bath. 7 (FIG.2.2).

This is because the surface of the polyester fiber is full of C-O-C (ether) linkages that are

hydrophobic, while the C==O (ester) linkages that are hydrophilic face towards the

interior of the fiber.

FIG.2.2 Dye on PET in HT dyeing (l30oC/1 h).

Dye on PET in HT dyeing (l30oC/1 h). Dye: C.I. Disperse Brown I (Micro disperse).

Concentration: a) 0.8 g/liter (unsaturated bath): (b)) 1.6 g/liter (over saturated bath); M:L

ratio 1:4000.

Since dye has to diffuse through the holes and space formed by the vibrations of

the chain segments of PET molecules, the shape and size of the dye molecule influences

the rate of dyeing. The higher the molecular size of dye, the higher is the space required

for the dye of diffuse. Because of this, as the temperature increases, the effect of the size

of a dye molecule on the rate of dyeing decrease; that is, the activation energy of

diffusion increases with the molecular weight of the dye. The rate and extent of

absorption of a dye are dedicated by the fiber structure, time and temperature of aqueous

dyeing or thermo fixation 9 Disperse dyes are combined to produce mixed shades.

Neither the rate nor the equilibrium adsorption of dyes in mixture is influenced by the

presence of the other dye 8The dyes build up on PET, independent of each other, up to

their saturation values. This is also the case with dyeing from an organic solvent 7

2.4 HT Dyeing

The mechanism of dyeing PET with nonionic dyes in an aqueous dispersion has

been investigated by many workers. Earlier investigation shows that dyeing involves the

attraction of positively charged particles of suspended dye to negatively charged fiber

surfaces to build up a surface layer of dye particles. Subsequently, the solid dye dissolves

in the fiber to form a solid solution. This mechanism, which was first suggested for

dyeing cellulose acetate with disperse dyes by Kartaschoff 17 is now rejected. It is now

established that dyeing takes place in a saturated solution of dye in an aqueous bath the

suspended particles in dispersion form a reservoir of dye that replenishes the solution as

the dye molecules are removed from the dye bath by the fiber. The dye in solution is

assumed to be in a monomeric form even though experimental difficulties prevent any

conclusive proof from being obtained on the monomolecular state of dye in solution.

Disperse dyes have definite water solubility. The solubility of a dye in the bath increases

with temperature.

Dyeing takes place in three simultaneous steps: (a) dissolution of dye particles in

the bath to give a dye solution, (b) adsorption of the dissolved dye from solution on to the

fiber surface, and (c) diffusion of adsorbed dye from the fiber surface to the interior of

the fiber substance.

2.5 COTTON:

Cotton is a linear cellulosic polymer. The repeating unit in the cotton polymer is

Cellobiose, which consists of two glucose units. Cotton consists of about 5,000 – 10,000

cellobiose units, that is, its degree of polymerization is about 5,000 – 10,000. It is a very

long, linear polymer, about 5,000 nanometer in length and about 0.8 nanometer thick.

The cotton fibres are amongst the finest in common use.. Such very fine fibres permit the

manufacture of fine, lightweight cotton fabrics and garments, etc,. Cotton is a very fine

fibre with little variation in fibre diameter. The fibre length to breadth ratio of cotton

ranges from about 6000: 1.

The most important chemical group in the cotton polymer is the hydroxyl (or) –

OH group. These are also present as methylol groups (or) CH2OH. Their polarity gives

raise to hydrogen bonds between –OH groups of adjacent cotton polymers. Vander

Wall’s forces also occur but compared with the hydrogen bonds, the van der wall’s forces

are of little significance.

Cotton is a crystalline fibre. Its polymer system is about 65 –70 % crystalline and

about 30 – 35 % amorphous. Therefore, the cotton polymers are well oriented and

probably no further apart than 0.5 nanometer, in the crystalline regions. This is the

maximum distance across which hydrogen bonds can form between polymers. Hydrogen

bonds are the dominant and most important force of attraction present in the polymer

system of cotton. For this reason, van der wall’s forces, which are also present, have little

relevance.

2.6 MECHANISM OF DYEING

2.6.1 The internal surface of fibers and its importance

The natural fibers (i.e.,) the cellulosic and protein fibers have exceedingly large

internal surfaces, which are the walls of the channels between the bundles of long chain

molecules composing the fibre. The number of such channels is immense, of the order of

ten million in the cross section (e.g.,) cotton or a wool fibre, and the total surface of their

walls is of the order of 100 m2/g, (or) five acres per lb. This is about one thousand times

as large as the outer surface of the fibre.

When the fiber is wetted, water rapidly penetrates and swells a large proportion of

these channels. Dyes in solution are then able to diffuse into the channels (or) pores.

They can however, enter only a relatively small proportion of the total internal

space, because the remainder is in pores too small to admit a dye molecule. Many of the

synthetic polymer fibers have much less internal surface than the natural fibres, but the

dyes used with such fibers are able to penetrate between the fibre molecules even though

water cannot always do so.

Dyes are surface active substances, (i.e.,) when dissolved in water their molecules

tend to concentrate more closely together at a surface than in the body of the solution.

The surface can be between the solutions and either air (or) a fibre. The first action in any

dyeing operation is therefore the concentration of dye molecules that as much of the

internal surface of the fibre as they can reach. The concentration so produced is however

not usually sufficient to give a usefully deep coloration to the fibre and for such

coloration other factors must be brought into play.

These are the chemical forces, which can operate between a dye molecule, and a

fibre molecule, which are classified below, and also those between the dye molecules

themselves, which can cause their association into larger units.

2.6.2 Chemical Forces Responsible For Dyeing

Broadly, four main chemical effects are subsequently responsible for the

substantively of the dye for the fibre. They are,

1. Hydrogen Bond

2. Non Polar or Wander Walls force

3. Electrostatic or ionic forces and

4. Covalent Bonds.

These seldom act in isolation; usually at least two operate in any dyeing process.

Additionally, the so called ‘hydrophobic bond’ may be involved.

2.7 Cyclodextrins:

Cyclodextrins are crystalline, water soluble, cyclic, non-reducing,

oligosaccharides built up from six, seven, or eight glucopyranose units. Cyclodextrins

have long been known as products, which are able to form inclusion complexes. They

used to be, however, no more than scientific curiosities due to their limited availability

and high price. As a result of intensive research and advances in enzyme technology,

cyclodextrins and their chemically modified derivatives are now available commercially,

generating a new technology: the packaging on molecular level. They have circular,

conical configuration, where the height is about 800 pm and the inner diameter of the

cavity is from 500-800pm. (vogtle, 1991; weber, 1987).

FIG.2.3 Structure and dimensions of CD

CD is a cyclic polymer of alpha-D-glucopyranose. The common cyclodextrins

used in chromatography are the alpha-, beta- and gamma-cyclodextrins which have been

shown to contain 6 (cyclo-hexamylose), 7 (cyclo-heptamylose) and 8 (cyclo-octamylose)

glucose units, respectively. These cyclic, chiral, torus shaped macromolecules contain the

D(+)-glucose residues bonded through a-(1- 4)glycosidic linkages.

The most stable three dimension molecular configuration takes the form of a

toroid with the upper (larger) & lower (smaller) opening of the toroid presenting

secondary and primary hydroxyl groups respectively to the solvent environment. The

interior of the toroid is hydrophobic as a result of the electron rich environment provided

in large part by glucosidic oxygen atom.

FIG.2.4 Cyclic shaped CD

It is the interplay of atomic (Vander walls), thermodynamic (hydrogen bonding),

and solvent (hydrophobic) forces that accounts for the stable complexes that may be

formed with the chemical substances which in the polar environment of the CD cavity.

The complex exists in an equilibrium depended upon the concentration of the CD, the

guest chemical and water.

FIG. 2.5 Torus shaped CD

Once the molecular has entered the cavity, the “goodness of fit”, as determined by

the weaker interactions taking place in the cavity, will make the final contribution to the

association component of the equilibrium process. These week forces can create selective

interaction similar to those of enzymes.

FIG. 2.5 Activity of CD

The properties of CD enable to them to be used in a variety of different textile

application. CD may act as a auxiliaries in washing & dyeing process. & they can also fix

on to different fibre surfaces. Owing to the complexing abilities of CD, textile with the

functional properties to be prepared this project aim is to cross link CD molecules on

hydroxyl groups of PEG & cellulose via BTCA4CD are macro cyclic compounds built

from glucopyranose units linked by α ( 1,4)-glycosidic bonds (frendenberg, 1948;

vogtie, 1991). CD can be obtained by enzymatic degradation of starch. In this process

compounds with 6-12 glucopyranose units per ring are produced. Depending on enzymes

and how the reaction is controlled the main product is, α, β or γ, cyclodextrine (6, 7 & 8

glucopyranose units respectively). β- CD is the most commercial interesting of the three

natural CD because of the easy production, availability, cavity diameter and price. It is

most widely used and presents at least 95% of all produced and consumed CD (Szejtli,

1994), the inner diameter of β-CD cavity is from 600-680 pm (Szejtli, 1996;

Jozwiakowski, 1985) and can accommodate aromatic compounds such as volatile

molecules and pharmaceutical compounds. New concept for modification of textile

substrate is based on the permanent fixation of super molecular compounds, such as CD

on the material surface and thus imparts new functionality to the fabric(Knittel,2003).In

such a way that treated substrates will be important for medical and hygienic textiles for

garment and home textiles( Buschmann,1990). From the structure of β-CD it is evident

that it can not form direct co-valent bond with textile fibres.Polycarboxylic acids like

1,2,3,4 BTCA are well Non-Formaldehyde Cross Linking Agent, which can react with

OH group of PEG & Cellulose and form stable ester bonds (Lewis, 1997; Yang, 1991;

Martel,2002).

Molecules, or functional groups of molecules being less hydrophilic than water,

can be included in the cyclodextrin cavity in the presence of water, if their molecular

dimensions correspond to those of the cyclodextrin cavity. The formed inclusion

complexes are relatively stable and rapidly separate from the solution in crystalline form.

One, two or three CD molecules contain one or more entrapped guest molecules. This is

the essence of molecular encapsulation, the packaging on molecular level. Molecules of

poorly soluble drugs, rapidly deteriorating flavors, volatile fragrances, toxic pesticides or

dangerous explosives, even gases can be encapsulated. The capsules of molecular size are

the cyclodextrins. Almost all applications of cyclodextrins involve complexation. In

many cases complexes are separated in more or less pure form and utilized as crystalline

substances (drug and flavor complexes) while in other cases the complexation process is

only a transient state, and becomes apparent through the final result(CD-catalysis,

separation of mixtures.)

Up to quite recently cyclodextrins have been considered exclusively as “empty”

capsules of molecular size. Recent studies revealed such a broad versatility in their

application, that they can be considered as a new group of industrial basic materials. CDs

are besides being “molecular capsules”, reagents in analytical chemistry and diagnostics,

raw materials for the production of derivatives and polymers, biologically active

substances, etc.

Research Objective of this Project:

To dye P/C in single stage process by using Disperse dyes

To save water, energy, time due to single stage process

To replace the surfactant & alginate by CD to face BOD, COD

Problem

To enhance the functional property of the P/C fabric

To minimize effluent problem due to shortening processes

EXPERIMENTAL METHODOLOGY

MATERIALS:

Fabric: 67:33 Polyester: Cotton Knitted Sample.

Yarn: 67:33 and 50:50 Polyester: Cotton Blended Samples.

Dye stuff: Yellow C4G H/C

N.Blue 3G 200%

Scarlet BR

Special Auxiliaries: β-Cyclodextrin

Polyethylene glycol with m.w 400

BTCA

Sodium Hypophosphite

And all other chemicals are in laboratory reagent grade

METHODS:

Scouring and Bleaching:

The samples were scoured and bleached by the Combined Process at 80 ºC for 45

min., with a solution containing 2 gpl Non-Ionic Detergent, 2 % Hydrogen Peroxide and

2 % sodium carbonate etc, Washed with Hot Water, Cold Water, Squeezed and Air

Dried.

Chemical Treatments:

Table

Methods Treatment

U Untreated

A Samples Treated with PEG then steaming at 160º C for 2 min. Finally the

samples were thoroughly washed with tap water and air dried.

B Samples Treated with a mixture of PEG and Sodium hydroxide solution

(95.5%/4.5% w/w) to wet pick-up of 100 % expression then steaming at

160º C for 2 min.Finally the samples were thoroughly washed with tap

water and air dried.

C Samples Treated with a mixture of PEG and Sodium hydroxide solution

(95.5%/4.5% w/w) to wet pick-up of 100 % expression then steaming at

160º C for 2 min ; treated with CD in different

concentration(10,15,20,30,35gpl) along with BTCA-0.6% ,Catalyst-

SHPI-0.6% etc then Curing at 170º C for 2 min . Finally the samples were

thoroughly washed with cold water and hot water, air dried.

Dyeing:

All the dyeing was performed using HTHP Dyeing technique. The pH of the

liquor was maintained at 5.5 using acetic acid. Well wetted fabric was entered in to the

vessel with the disperse dyes-x%, dispersing agent-0.5% etc at room temperature and

then the temperature is gradually raised to 130ºC and work for 30-40 min .Finally, all the

dyed samples were thoroughly rinsed, soaped with 3 gpl Lissapol N(Non-ionic detergent)

at boil for 10 min, washed and air dried.

CHAPTER – 4

2.3. Testing and Analysis:

2.3.1 Determination of degradation of PET:

Carboxylic content of treated samples (A, B & C) was analyzed according to a

reported method10.This tests is useful to determine the degradation effect of PET causes

by alkaline and steaming, However the staining test can also carried out with Basic dyes

(Basic Blue 9 for 0.5%(o.w.f); Temp. 85ºC, Time, 60 min; MLR 1:100) to find

qualitatively through colour strength determination by CCM.

2.3.2 Dye Exhaustion percentage:

The dye uptake was evaluated by visible spectroscopy from calibration curve of

concentration versus absorption of the individual dye at its wavelength of maximum

absorption using shimadzu spectrophotometer. Dye exhaustion percent expressed as E%,

it was calculated as a difference between the dye concentration before and after dyeing.

i.e.

E %=( Cb-Ca/Cb) x 100---------- (2.1)

Where, E-Exhaustion percentage

Cb-The Dye concentration before dyeing

Ca- The Dye concentration after dyeing

2.3.3. Evaluation of K/S Value:

Colour strength (K/S Value) of the dyed sample was measured on Data Spectra

flash SF 600 Sectrophotometer.These values are computer calculated from reflectance

data according to kubelka-munk equation2

K/S= (1-R) ² / 2R---------------- (2.2)

Where-Light absorption co-efficient

S-Light scattering co-efficient

R- Reflectance of the dyed samples

2.3.4 Fastness Properties:

The fastness properties of all treated and untreated dyed samples to washing,

Rubbing and sublimation were assessed according to BIS Test methods (Bureau of

Indian Standards).The change in shade was visualized using grey scale and graded from

1 to 5, 1 indicates poor and 5 indicates excellent fastness properties (Light fastness were

graded from 1 to 8, 1 indicates poor and 8 indicates excellent fastness to light) 6

2.3.5 Surface Studies:

The surface of untreated and untreated samples were studied using SEM analysis,

the samples was mounted on a standard specimen stub and examined in a Jeol jxa-84 oh

Electron probe micro analyzer, Japan operating at 19 KV. A Thin Coating ( app. 10 nm )

of gold was deposited on to the sample and attached to the stub , prior to examination in

the SEM , to enhance conductivity and secondary electron emission characteristics of the

over growth .

2.3.6 Determination of Moisture Regain::

The alternative current (a.c.) electrical properties is very much useful to determine

the moisture regain of both treated and un-treated samples, which have been studied

using a programmable automatic RCI bridge (PH 6304 Philips), analyzing their

dependence on temperature and frequency. The a.c conductivity and electrical resistance

have been measured in the frequency range (5-20 KHz) over the temperature (24-

100ºC).Samples were in the form of tablets and silver rods was used as electrodes.

Sample temperature was measured using a pre-calibrated chromelalumel thermocouple

type K placed near the sample. All measurements were carried out in specially designed

cell.

2.3.7 X-Ray Diffraction:

Both treated and untreated samples were investigated by X-Ray diffraction

technique using Siemens D-5000(Computer controller) X-ray diffract meter, with Cu

target (1=1.542 Aº) and Ni filter. A continuous scan mode was used to scan 5 º <20> 65

in 0.05 step. The samples were in powder form.

2.3.8 Wettability :

A Simple test of Wettability of fabric is to cut small square specimens, ex.

1 “x 1“., and to drop them on to the surface of a beaker of distilled water .The time taken

for the specimens to make sink below the surface is observed , the shorter the time the

greater the wettability5

2.3.9 Soil Release Testing:

The tumbler test is used with the help of artificial soil to find out Soil Release

property of both treated and untreated samples. 18 (See Annexure). The fabric samples

were soiled by using ISI procedure involving repeated (thrice) dipping of fabric in

standard soil, padding and drying. Standard soil contained coconut oil, fatty acid, white

oil, carbon black in tetrchloroethylene solvent. Soiled samples were soaped at 95ºC for 10

min in nonionic detergent (4 gpl) followed by washing with distilled water. The soiled as

well as washed samples were visually compared to assess the extent of soil removal and

graded21 .

2.3.10 Pilling Tendency:

ASTM has recommended different test Methods for determining pilling resistance

and other surface effects such as fuzzing. Accelerator test methods were used for pilling

tendency testing and it covers the method for using the impeller tumble abrasion testing

machine to evaluate the pilling propensity of knitted fabric32 .The Grading of pilling are

given in ANNEXURE

CHAPTER 5

RESULTS AND DISCUSSION

Polyethylene Glycols are widely used in textile in processing as additives for

improving fixation of disperse dyes to specific fibre type. For example , cellulosic and

cellulosic fibre blends exhibit improved dye ability when concentrations of up to 10%

PEG(av. M.w of 100-600) were used in the dye bath 26Similar improvements were

observed when PEG was used as dye bath additives in the dyeing of P/C fabrics with

disperse dye 20 .

Cyclodextrins can be considered as a new class of Textile auxiliary’s substances

for the textile Chemical processing industry; Very important is that their COD in the

waste water is lower than that of the usual textile auxiliaries. While the COD is 2020

mg/g for NP-10(a polyester); 1930 mg/g for Uniperol O (a fatty alcohol polyglycol ether;

BASF), for β-CD this value is only 1060 mg/g 19 . For coloration of PET fibres , so-

called disperse dyes are used, which are very poorly soluble in water(0.1-10 mg/L)

Without using solubility-enhancing agents(surfactants), uniform dyeing is not possible .

CD, however, can replace the surfactant24.A New finish was developed for easy removal

of sweat degradation products from the textile by preventing their penetration into the

fibre . A Cotton textile was impregnated with a composition containing

dimethylolethylene urea, catalyst and β-CD (5-50 gpl) and fixed. The textile was treated

with in a bath containing 10 gpl butyric acid and as the concentration of β-CD increased

in the finish bath , the concentration of butyric acid in the fabric increased 30

This project’s intention was to make the use of the positive aspects of the

mentioned methods for modifying the surface of the fabrics and we choose to apply a

hybrid approach. The influence of the type of treatments, carboxylic content, dye uptake,

Surface topography, fastness properties, electrical properties and the structural properties

of the treated and untreated samples are discussed below.

Table-1: Carboxylic Content & Colour Strength of Various treated Samples of

Carbonized P/C Fabrics Dyed With Basic Dyes.

Carbonized P/C

Sample

Carboxylic content m.eq.100 gr.fabric Colour

Strength

(K/S)

Untreated 31.2 0.23

A 48.4 0.29

B 290.6 2.54

C 180 2.2

It is seen from Table -1, that the carboxylic content in the case of treated sample

is higher than the un-treated ones; and that the mode of increasing is depending upon the

type of treatment. The hydrolysis of polyester takes place not only at their free ends, but

also in other positions, thereby the increase in carboxylic content was continued and

reached 290.6 m.eq./100 gr.treated samples. The colour strength of samples dyed with

basic dye is thus indication of hydrolysation and it can provide an assessment of the

degree of hydrolysis. It was found that K/S increased as the concentration of carboxylic

groups increased, even though the concentration of the basic dye in dyeing bath was held

constant. On the other hand it was found that the values of carboxylic contents have

decreased and it might be possible that the action of PEG is more chemical in nature. The

new formed free carboxylic end groups react with hydroxyl groups in PEG and CD

thereby decreasing its content and forming the block copolymer of PET and PEG

[Block A][Block B][Block A][Block B] and Grafting with CD

Where, Block A- PET

Block A- PEG

Conversion of Carboxylic groups to Carboxylate Anion:

When fabrics were treated with BTCA & CD, esterification between BTCA,CD

and hydroxyl group of cellulose & PEG occurred at elevated temperature . After washing

the un-reacted acid, the carbonyls retained in the fabrics and existed in three forms,

namely Ester, Carboxylic acids and Carboxylate anions

The formation of such block co-polymer is well established3.Nevertheless, A

Distinct feature of CD is its ability to form inclusion compounds, where inclusion

formation is mainly affected by the geometric shape of the molecular rather than

chemical interactions. The hydrophobic portion of the guest molecule is positioned such

that maximum contact with the non-polar cavity is possible while the hydrophilic portion

is located on the outer surface of the inclusion complex such that it is near the proximity

of the hydroxyl groups of the host 23

Grafting of β-CD on to OH group via BTCA

The proposed Grafting reaction of β-CD on to OH group via BTCA

Qualitative Determination of β-CD Molecules on the Textile Substrates

β-CD Molecules on textile substrate was determined by phenol Red and

Phenolphthalein. Phenol red forms coloured complex with β-CD, So, phenol red changes

colour from red to yellow when CD is present on the substrate.

Fig-3

Change of phenol red colour from red( for untreated) to yellow for treated in solution

containing 30 gpl of β-CD, 6 gpl of BTCA , 6 gpl of SHPI; Thermofixed and rinsed in

cold water and washed at 60ºC for 30 min.

Figure – 4 presents the change in the colour of phenolphthalein from carmine red

for untreated textile substrate to colourless

Fig-4

Change of phenolphthalein colour from carmine red( for untreated) to colour less for the

fabrics treated in solution containing 30 gpl of β-CD, 6 gpl of BTCA , 6 gpl of SHPI;

Thermofixed and rinsed in cold water and washed at 60ºC for 30 min.

Dyeing Properties:

The probable reason for these observations may be explained as follows: The two

components viz. cotton and polyester, present in the blend possess different

characteristics individually. Cotton fibre constitute of a continuous network of cellulose

chain which come together at certain places to form an ordered arrangements called

crystallite or miscelle.The size of the spaces between the micelles in the water swollen

fibre covers the maximum size of molecule which can penetrate into the closely packed

structure of the micelles. The pore size available in cellulosic molecule is much higher

compared to disperse dyes which are usually small molecular weight compounds .Thus to

and free movement of dye particle occurs without any sort of disruption from the dye

liquor to the fibre and vice versa .Due to this virtually no dyeing results .However, the

pore size in the fibre structure probably reduces in the presence of PEG, thereby allowing

dyeing to occur. On the other hand, the compact structure of polyester allows minimum

pore size available for the penetration of dye molecule. It is well established that for

polyester, penetration of disperse dyes is more prominent at higher temperature due to

more availability of free volume18.In the present study, the presence of PEG hinders the

usual penetration of the dye molecules.

Effect of. CD’s conc. on Dye exhaustion (E %) and Colour strength (K/S) of treated

and untreated P/C Blends dyed with Disperse dyes

CD

Conc.

(gpl).

C

E% K/S

0 24 2.4

10 37.8 4.2

15 44.2 4.8

20 48.2 4.2

30 52.5 5.2

35 52.1 5.2

Effect of. Treatments on Dye exhaustion (E %) and Colour strength (K/S) of

treated and untreated P/C Blends dyed with Disperse dyes

Untreated A B C*

E% K/S E% K/S E% K/S E% K/S

24 2.4 29.4 2.9 61.9 4.4 64.5 6.2

*30 gpl of CD Treatment

The dye exhaustion and colour strength increases by increasing the Conc., of CD

up to 30 gpl then the effect gets no change due to saturation. The type of treatment also

determines the dye exhaustion and colour strength that means the alkaline and PEG

treatment alter the characteristics of fibre. The swelling of PET fabric is favored at

steaming temperature, thus facilitating the diffusion of saturated steam inside the fabric

thereby speeding the removing of oligomers, opening up and modifying the fabric

structure, as well as enhancing the segmental mobility, this speeds the diffusion of the

dye in to the fabric and increases its dye uptake29.

In case of P/C blend ,the presence of PEG, the K/S Value is more for cotton

component and less for polyester component , & it is possible that the pore size available

in the cotton fibre structure reduces in the presence of PEG thereby making the cotton

fibre as dyeable with disperse dyes1

Surface Topography:

The Surface of untreated and treated samples was studied using SEM analysis

technique. Photomicrographs corresponding to different investigated samples are

depicted in the following figures.

Fig-2 SEM for the surfaces of untreated sample

Fig-3 SEM for the surfaces of Samples Treated with PEG then steaming

Fig-4 SEM for the surface of Samples Treated with a mixture of PEG and Sodium

hydroxide solution (95.5%/4.5% w/w) to wet pick-up of 100 % expression then

steaming

Fig-5 SEM for the surface of Samples Treated with a mixture of PEG and Sodium

hydroxide solution (95.5%/4.5% w/w) to wet pick-up of 100 % expression then

steaming at 160º C for 2 min ; treated with CD then curing at 170º C for 2 min

The untreated sample has a smooth surface (Fig-1). When these samples were

treated with PEG & steam the surface becomes less coarse (Fig-1). On the other hand the

surface of sample treated with sodium hydroxide and subjected to steam have changed

very unevenly , the fabric becomes coarser with pits and pores as shown in (Fig-3) .After

treatment with the alkaline PEG, CD the surface of the sample becomes much coarser

compared with other samples(Fig-4). This indicates that sensitive presumably amorphous

areas are susceptible to attack. The above mentioned surface observation is in full

agreement with the results listed in table of Colour strength analysis.

Fastness Properties:

Fastness properties of treated and untreated samples are shown in Table-4.It is

clear that the present treatments improve the sublimation fastness property with high

level rather than light and washing fastness since the water loving groups like hydroxyl,

Carboxyl group etc will enhance the sublimation fastness property in the dyed material.

Nevertheless, the fastness property of the given dyed material is mainly depends upon

the percent blend proportion that means the given treatment produce good fastness

property if the PET portion is more. The washing and Rubbing fastness get minimized if

the depth of shade gets increased.

Table-4 Fastness properties of Treated and untreated samples dyed with Disperse

dyes

* Fastness Grades for

67:33 Blends 50:50 Blends

Light Medium Dark Light Medium Dark

W R S W R S W R S W R S W R S W R S

U 3 3 3 3 3 3 3/2 2 3 4 4/3 4/3 4/3 4/3 4/3 2 3 3

A 3 3 4/3 3 3 4/3 3 3 4 4 4/3 4 4 4 4/3 3/2 3 4/3

B 4 4/3 4/3 4 4/3 4/3 4/3 4/3 4 4 4/3 4 4/3 4/3 4 3/2 4/3 4

C 4 4 4 4 4 4 4 4/3 4 4 4/3 4 4/3 4/3 4 3/2 4/3 4

*Samples (U-Untreated; A, B and C Treated)

Where, W- Wash fastness; R-Rubbing fastness; S-Sublimation fastness; U-Untreated

sample

Moisture Regain:

The moisture regain of treated and untreated samples was determined. It was

found that treatments under investigation are accompanied by an increase in the moisture

regain. The most pronounced effect is obtained in case of treatment C and D.This could

be due to the outstanding increase in carboxylic contents and hydroxyl groups after such

treatment and out of which sample D has more moisture regain than others due to

carboxylic content and free hydroxyl group present in the CD Structure.

Table-5 Moisture Regain of Treated and Un-treated sample

Samples Moisture Regain

(%)

Untreated 0.42

A 0.96

B 1.33

C 1.52

D 1.71

X-Ray Investigation:

The X-Ray diffraction patterns for treated and untreated samples are shown in

Fig-6.

X-ray Diffraction Patterns

It is seen that all patterns have the same three peaks at 20 of 17.8º, 23.2º and 26.5º

respectively. These three peaks correspond to the 010,110,100 spacing. This indicates

that all such samples have the same triclinic unit cell with interplaner spacing, very close

to that previously reported36

Table-6: D-spacing and Crystallinity of treated and untreated samples

Samples D-spacing Crystallinity

(%)010 110 100

Untreated 5.11 3.989 3.52 24.1

A 5.257 - 3.39 25.9

B 5.10 3.93 3.54 32

C 5.133 3.9 3.50 27.7

Table-6 indicates the measured interplaner spacing for all the samples, where

minor changes in these values were observed. These values fluctuate depending on the

type of treatment .It was found that the untreated sample contains 24.1% crystalline area.

The treated samples with PEG with alkaline solution and CD contain 25.9 and 27.7 %

respectively, crystalline area. So, structurally, i.e. ., in terms of the total crystalline area,

there is no much significant change. Thus, it can be assumed that, upon treatment with

PEG and with its alkaline solution before CD treatment, the overall crystalline areas

remain the same. It seems that the treatment with treatment with PEG and sodium

hyadroxide increases the degree of crystallinity; a point that contradicts with dyeing

properties and MR of modified samples (Table-colour strength & Regain). As the

crystallinity increases, the dye uptake also increases. Such contradiction would not

happen if we consider the crystallite size. Increase of the colour strength with increasing

the crystallinity confirms that a change in the crystallite size has occurred under the

present treatment condition13Correspondingly the amorphous regions accessible to the

dye molecules increases due to the decrease of crystallite parts.

Electrical Properties:

The electrical resistance R(w) and a.c.conductivity sa.c(w cm) power -1 for all the

samples were measured in temperature 24-100ºC and at one frequency ( 20 K Hz) .

Variation of the R and sa.c values with change in the type of treatment is given in Table-7

Table-7 Electrical resistance R (w) and a.c Conductivity s a.c (w cm) power-1 of the

treated and untreated samples.

Property

**

Temp. Untreated A B C

Rx10 8

w

24 1.7 0.9 1.8 0.8

60 1.7 0.6 1.6 0.6

100 1.6 0.4 1.3 0.4

S a.cx10 -10

(W cm) -1

24 7.2 13 9 16

60 7 23 9.4 26

100 7.7 28 11.2 36

** Measuring was carried out at one frequency (20 KHz)

Based on the obtained data, one could conclude the following: a) a slight decrease

in R and a little increase in s a.c values takes place after treatment with NaOH solution in

spite of the significant increase in moisture regain of the sample b) Changes in the values

of both R and s a.c are more pronounced in the case of sample C.Such treatments

significantly decrease R (2-4 times) and markedly increases s a.c ( 2-5 times) values, as

compared with those for untreated samples , and illustrates the positive effect of

treatments with PEG on the electrical properties of Sample. This result postulates the

amount of MR increasing after treatment with PEG and CD through resistance and

conductivity changes phenomenon.

Wettability:

Wettability of sample was measured by noting the time of sinking for a 5x5 cm

piece under constant weight in distilled water21. The Table-8 shows the different wetting

time for different type of treatments. Here, the water absorbing groups like carboxylic,

hydroxyl etc increase the wettability of the samples rather than untreated one. Both PEG

and CD having hydroxyl groups in their structure and these groups cause more

hydrophilicity.However, the wettability and hydrophilicity is also depends on the percent

proportion of cotton portion. Generally, the water absorbing groups increases the

wettability of the material, it was known by comparing the different sinking time for the

different treated samples. If the sinking time is low the wettability will be more and so

on.

Table-8 Wettability of treated and untreated samples

Samples

Wetting Time( Sec)

Polyester P/C

67:33 50:50

Untreated 48 28 16

A 30 13 10

B 12 5 4

C 4 3 2

The effect of caustic treatment on both PET and cotton is positive in nature with

respect to wettability. The reaction of caustic on PET is takes in place in the following

manner according to specific time, temperature, concentration etc.

Effect of Caustic on Polyester

Sodium Terephthalate Ethylene Glycol

Soil Release Testing:

The polyester fabrics show a higher extent of soiling than P/C samples. However,

in both cases alkali treatment and PEG treatment leads to improvement in soil removal

characteristics. When the sample is treated with PEG and NaOH, dried and baked, some

ester interchange between teraphthalate sodium polyglycol oxide takes place and

hydrophilic grafts-COO (CH2CH2O) n H-are formed on the fibre. The treatment shows an

improvement in soil release and re-deposition properties as well as a drop in static

charges even after treating with CD27, 18. And When CD bound chemically with fibres, it

provides enhanced hydrophilicity, it performs easy removal of sweat and sweat

degradation Products from the textiles, since the CD will not allows the degraded

compounds in to the core of the fibre16.However, the soiling also depends on static charge

generation property and the percent proportion of hydrophilic fibre present in the blended

fabric.

Table-9 Soil Release Property of treated and untreated samples

Samples

Soil Removal (Grade)

Polyester P/C

67:33 50:50

Untreated C B B

A B A-B B

B A-B A A-B

C A A A

Pilling Tendency:

Synthetic fibres are easily brought to surface of the fabric than cellulosics,

because of their smooth surface and circular cross-section. Due to their higher

mechanical strength and abrasion resistance, the pills remain for a longer time21. The

Pilling tendency depends on the type of fibre in the fabric (see annexure). The

treatment with the caustic soda solution weakens the polyester fibres resulting reduction

in the pilling tendency.

Fig- Effect of Caustic on Polyester

Sodium Terephthalate Ethylene Glycol

In the caustic treatment, the polyester is hydrolyzed to produce water soluble sodium

terephthalate and ethylene glycol resulting decrease in tenacity will takes place and it

produce low pilling tendency formation .

Although, pilling may be de-aggravated by reducing electrostatic pick up of tint,

dirt, or other foreign matter due to making the fibre as more moisture regain and

hydrophilicity.

Table-10 Pilling Grade of treated and untreated samples

Samples

Pilling Grade

Polyester P/C

67:33 50:50

Untreated 2 3-2 3

A 2 3 3-2

B 2-3 4-3 4

C 4 5-4 5-4

CHAPTER 6

CONCLUSION & SUGGESTIONS

Disperse dyes do not posses any affinity for the cotton component of the P/C

Blend when applied using conventional dyeing techniques. Further, tone-in-tone effect on

such blends can not be achieved by using only one dye in a single dye bath application.

This can be readily done by treating with PEG, NaOH, and CD etc. Nevertheless; CD

improves the other functional properties like Soil release, hydrophlicity, Crease recovery

also (since the BTCA is used in CD Treatment, Which is an non-formaldehyde cross

linking agent). These compounds improves the dye ability of disperse dyes on P/C

Blended fabric. The fastness properties are also slightly improved due to the presence of

PEG and CD.

The successful application of disperse dyes on P/C Blend with the help of PEG &

CD bring out numerous advantages such as,

a) Dyeing of P/C in a single stage process by using Disperse dyes only

b) Saving of water, energy, time (due to single stage process)

c) Replacing of conventional surfactants & thickeners by CD (It will give low

BOD & COD Value than conventional one)

e) Enhancement of functional property of the P/C fabric by means of CD

f) Minimizing of the effluent problem due to shortening processes, re-placing of

Surfactants etc

g) Which is an Economical process since it saves time, cost etc

CYCLODEXTRIN might play a significant role in the dyeing of P/C blends and might be used

Substitute for conventional Surfactants in P/C processing;

When bound chemically with fibres, it provides enhanced hydrophilicity

It perform easy removal of sweat and sweat degradation

Products from the textiles

APPENDICES

Appendix 1

Effect of NaOH on polyester during Alkali Treatment21.

Treatment Polyester P/C(67:33)

Concentration

(%)

Time

(min)

Wt.loss

(%)

Weft

strength

(Kg)

Wt.loss

(%)

Weft

strength

(Kg)

0 0 0 72.5 0 36.5

0.5 15 <1% 72 <1% 36

0.5 30 <1% 72 <1% 36

1 15 <1% 72 <1% 36

1 30 <1% 71.5 <1% 35.5

Appendix 2

Modification in Properties on Alkaline Treatment21

Treatment Polyester P/C(67:33)

Concentration

(%)

Time

(min)

Wetting

time

(Sec)

Soil

Removal

(Grade)

Wetting

time

(Sec)

Soil

Removal

(Grade)

0 0 48 C 28 B

0.5 15 - B 6.5 A-B

0.5 30 8.5 A 4.0 A

1 15 2.5 B 2.5 A-B

1 30 2.0 A 1.5 A

A- Good soil Removal, B-Moderate soil removal, and C-Poor soil removal

Appendix 3

Composition of Artificial soil18

Ingredients Amount %

Peat moss 38

Cement 17

Kaolin clay 17

Silica 17

Carbon Black 1.75

Red iron-oxide pigment 0.5

Mineral oil 8.75

Appendix 4

Typical pill curves for common textile fibres18

Appendix 4

Pilling Grades*

Rating Description Points have been considered

5 No Change No visual change

4 Slight Change Slight surface fuzzing

3 Moderate Change Isolated fully formed pills

2 Significant Change Distinct fuzzing

1 Sever Change Dense fuzzing

* (Physical Testing of Textile by B.P.Saville, published by Textile Institute, 2000, pp 191

REFERENCES

Titles

1 Agarwal.B.J and Patel B.H & Vaidya.A.A., May-June (2002).,Studies on

single –bath application of dyes on polyester/Cotton Blends, ,The Textile

Industry & Trade Journal , pp.77.,

2 Billmeyer Jr., F.W., and Ssltman,M., (1981).,Principles of Colour Technology

2nd edition : John Wiley & sons: New York; pp.140

3 Blaeser .,Hoechst-Colanese-Corp., , E.J.U.S. Patent 4975233)

4 Bojana voncina and Alenka Majcen le Marechal, Proceedings of the Textile

Institute 83rd World conference May 23-27, 2004., β-CD in medical &

Hygienic Textiles.

5 Booth., J.E., Principle of Textile Testing, pp.332., CBS Publishers , New

Delhi.

6 Bureau of Indian Standards.,(2001).,Handbook of Textile Testing, Part 4

Identification and Testing of Dyestuffs and Their Colour Fastness on Textile

Materials( First Revision), Published by Bureau of Indian Standards, New

Delhi 110002 ( July 2002), (Washing: IS: 687-1979 pp.137-138), (Rubbing:

IS: 766 – 1988pp. 193-194),( Sublimation: IS: 975-1988 pp.203-204)

7 Datye.K.V., Colurage., 24(4)(1977), pp.27

8 Datye.K.V.,Pitkar,S.C.and.Rjendiran,R.,Indian J.Tech.,

pp.5(1966),101;8(19700,6

9 Datye.K.V.,Pitkar,S.Cand Rjendiran,R., Indian J.Tech.,

pp.4(1966),101;8(19700,6

10 Daul, G; Reinhyardt, R.K and Reid, J.D., (1953).,Textile Research

Journal ,pp.23,719

11 Daul, G; Reinhyardt, R.K and Reid, J.D., (1953).,Textile Research Journal,

23,719

12 Han.L., Wakiada,T and Takagishi.,T.,(1987). Textile Research Journal, 57,

(9),519

13 Han.L.,Wakiada, T. and Takagishi., T., (1987) Textile Research Journal ,

pp.57, 519

14 Hebeish,A., Shalaby,S.E.and Bayazeed,A.M.,(1981)Jounal of Applied

Polymer Science 22, 1359(1978) & Hebeish,A., Shalaby,S.E., and Bayazeed,

A.M., Journal of Applied Polymer Science,26,3253

15 Jozsef Szejtli ., (2003) Cyclodextrins in the Textile Industry, , CYCLOLAB

Research and Development Laboratory Ltd., Budapest, Hungary. ©2003

WILEY-VCH VERLAG GmbH & Co.KGaA,Weinheim., Starch/Starke 55

pp.191-196.

16 Jozsef Szejtli., (2003) Cyclodextrins in the Textile Industry, Starch/Starke

55(2003) pp191-196, , CYCLOLAB Research and Development Laboratory

Ltd., Budapest, Hungary. ©2003 WILEY-VCH VERLAG GmbH &

Co.KGaA,Weinheim

17 Kartaschoff.V, Helv.Chem.Acta, pp.8 (1925), 928

18 Keshav V. Datye and Vaidya., (1984) – “Chemical processing of synthetic

fibres and blends” –– pp. 183-190.

19 Knittel. D., Buschmann H.J., Schollmeyer E. (1992): Taylor-made properties,

B+W/B+M (Bekleieidung+Textile), pp. 12, 34-40)

20 Krichevskii, G.E., (1984)Textile Technology 37,(4),168 (1984) vide ,

Chemical abstract , 101,112302

21 Kulrajani., M.L Polyester Textiles,. (1980)-Finishing of polyester and

polyester blend fabric by Achwal., W.B., pp 264,Puplished by Textile

Association, India

22 McGregor.R., and Peters., R.H., JSDC,.pp.81(1965),393;429

23 Myung .Hak .Lee, Kee Jong, Sohk-Won Ko (2000) Grafting onto Cotton fibre

with Acrylamidomethylated beta cyclodextrin and its application , , Journal of

Applied Polymer Science , Vol.78 , pp.1986-1991

24 Savarino,.P.,Viscardi,.G,Quagliotto.P ,Montoneri,E.,Barni.E,

(1990):Reactivity and effects of CD in textile dyeing ; Dyes Pigm., 42(2),

pp.143-147

25 Schnider,E.F.. ADR, 52(1963),370.

26 Shalimova, G ., Shulepova, O.I., Krutovskaya,I .V and Goncharaova, K.M.,

(1980)U.S.S.R Pat.763500, Sept. 30(1980);Chemical abstract,pp.84,32112,

27 Sheard , D.R., (1966),Rev.Textile Progress, 17466) .

28 Shenai.V.A and Nayak, N.K., Textile Dyer and Printer , 14(23), 25(1981),&

Gawish,S.M;Ambroise,G., American Dyestuff Reporter , 80(4),22(1991)

29 Shukla, S.R., HEDA, O.O.and Sligram, A.N., (1992)., American Dyestuff

Reporter, pp.81 (3), 37

30 Sibusawa.T, (1994)Effect of dispersants on the sorption isothems of non-ionic

dyes on polymers from water .Sen’I Gakkaishi,50(120 pp.605-607

31 Ten Breteler, M.R. Nierstrasz., V.A. and Warmoeskerken,. M.M.C.G. Textile

., December (2002) Slow-Release systems with Medical Applications,

AUTEX Research Journal, Vol. 2, No4, © AUTEX

32 Timmis,J.B., (1976). Dyer Inter,pp.156

33 Vaidya.A.A., (1988).,Production of Synthetic fibres, Prentice-Hall of India

Pvt. Ltd.,

34 Vaidya.A.A.,The Textile Industry & Trade Journal , pp.77.,May-June 2002

35 Wellman Inc. and Branum,J.B.EP Patent, 1248871,(2002), & Xin,L.,

Rultao,L., Lixia and G., Jouranal Applied Polymer Science, 89,

(6),1996(2003).

36 You-Lo,H and Zhishen,M., (1987) Journal of Applied Polymer Science ,

pp.33,1479