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 etc
1,

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 commercially
33
.
In the second method surface modification of PET fibres have been achieved using
various methods such as alkaline hydrolysis
28
graft polymerization of hydrophilic
monomers
14
, and steaming
12
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 etc
1,34
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 80-100
o
C. 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 T
g
(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-
130
o
C) 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 NO
2
, 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 T
g
.
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 T
g
.
An increase temperature of above T
g
, 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 (l30
o
C/1 h).
Dye on PET in HT dyeing (l30
o
C/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
8

The 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 BTCA
4
CD 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 method
10
.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 equation
2
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 wettability
5
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
graded
21
.
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 fabric
32
.The Grading of pilling are
given in ANNEXURE