Yaa Cationization Of Cotton Wool Past Times Using Chitosan For Reactive Dyeing To Avoid Electrolyte (Part-1)

Cationization of Cotton past times Using Chitosan for Reactive Dyeing to Avoid Electrolyte (Part-1)

Md. Obydullah

Md. Shibli Sadique
Dhaka University of Engineering & Technology,
DUET, Gazipur-1700, People's Republic of Bangladesh

ABSTRACT
This report presents finding on the possibility of dyeing of cotton fiber cloth alongside reactive dyes using chitosan instead of salt. Reactive dyeing is immediately the most of import method for the coloration of cellulosic fibres. Reactive dyes conduct maintain adept fastness properties owing to the covalent bonding that occurs alongside the in conclusion (primary as well as secondary) hydroxyl grouping of cellulose at alkaline metal status during dyeing. All the reactive dyeing systems need huge sum of electrolyte to exhaust the dye. These electrolytes are neither exhaust nor destroyed as well as so rest inwards the dye bathroom later dyeing. All the above, entirely 60-65% dye utilization is attainable fifty-fifty alongside the usage of tabular array salt inwards the normal dyeing systems. On the other hand, reactive dyeing pollutes the surroundings past times discharging highly colored reactive dye bathroom as well as higher electrolyte concentration. To retain the desired exhaustion of dyes alongside elimination of tabular array salt a convenient method is introduced for cotton fiber treated alongside chitosan showed a improve reactivity as well as dyeability. In this experiment, dyeing alongside chitosan instead of tabular array salt shown a improve possibility owing to the dye absorption test. The dyeing of chitosan treated sample-1, 2, 3 & four alongside NOVACRON RED FN-2BL (1%) dyes shows the absorption rating of 1.6, 1.7, 2.1 & 2.95 respectively at a given wavelength whereas tabular array salt treated sample (standard) demonstrate the absorption charge per unit of measurement 1.9. Dyeing shade varies for different molecular weight of chitosan but depression molecular weight chitosan give fifty-fifty shade.

CHAPTER 1
INTRODUCTION

1.1 Introduction
Reactive dyeing is immediately the most of import method for the coloration of cellulosic fibres. Reactive dyes conduct maintain adept fastness [1] properties owing to the covalent bonding that occurs during dyeing. Cotton is made of cellulose molecules which react alongside the dye. During reactive dyeing the hydrogen atom inwards the cellulose molecule combines alongside the chlorine (cl2) atom inwards the dyeing procedure as well as results inwards a bond. Reactive dyes used to dye cellulosic fibres. The dyes incorporate a reactive group, either a haloheterocycle or an activated double bond, that, when applied to a fibre inwards an alkaline metal dye bath, forms a chemic covalent bond alongside a hydroxyl grouping on the cellulosic fibre. There are unopen to benefits, because the reactive dye consists alongside Chromospheres of dye part, Bridging Groups, Reactive grouping bearing parts as well as Reactive groups. Reactive groups are the responsible for the fixation on alkali condition. All the reactive dyeing systems need huge sum of electrolyte as well as alkali to exhaust as well as cook the dye respectively. These electrolytes are neither exhaust nor destroyed as well as so rest inwards the dye bathroom later dyeing. All the above, entirely 60-65% dye utilization is attainable fifty-fifty alongside the usage of tabular array salt inwards the normal dyeing systems. Reactive dyeing pollutes the surroundings past times discharging highly colored reactive dye bathroom as well as higher electrolyte concentration. Higher electrolyte concentration inwards the effluent campaign worst effects such as- impairing the fragile biochemistry of aquatic organism, destructive laid on on concrete pipes if sodium sulphate is used equally electrolyte due to the formation of alumino-sulphato complexes which bully as well as fissure concretes alongside considerable alumina content. To retain the exhaustion of dyes without usage of salt, a convenient method is introduced for cotton fiber treated alongside chitosan showed a improve reactivity as well as dyeability. Chitosan is a non-toxic as well as chemically reactive, as well as biocompatible natural functional polymer, as well as has long been used equally a biopolymer as well as natural stuff inwards many fields. Recently, chitosan effects widely studied are antistatic, bacteriostatic, biocompatibility properties conferred on diverse textiles. According to unopen to previous experiences, wrinkle-resistance finishing alongside chitosan for cloth tin sack improve its wrinkle marking but its grip as well as mechanical belongings got worse to a certainly extent. Chitosan adsorption too increased the wet absorption of the fibers. Chitosan alongside lower molecular weight increased the hydrophilicity of the treated fibers, but chitosan alongside higher molecular weight, decreased it.

1.2 Objectives of the Project as well as Thesis
The original objectives of the report to increment the dyeability reactivity dye past times using eco-friendly biodegradable chitosan.

To instruct desired exhaustion of dye inwards dyeing of cotton fiber cloth alongside reactive dyes without using salt.
To avoid the tabular array salt which impart inwards the environmental pollution.
To improve color intensity of cotton fiber cloth past times using chitosan which render to a greater extent than dye sites than that of untreated fabric.
To improve the dye uptake as well as too to trim the effluent load.

CHAPTER 2
REACTIVE DYE

2.1. Reactive Dye
A dye, which is capable of reacting chemically alongside a substrate to shape a covalent dye substrate linkage, is known equally reactive dye. Here the dye contains a reactive grouping as well as this reactive grouping makes covalent bond alongside the fibre polymer as well as human action equally an integral part of fibre. This covalent bond is formed betwixt the dye molecules as well as the in conclusion –OH (hydroxyl) grouping of cellulosic fibres on betwixt the dye molecules as well as the in conclusion –NH2 (amino) grouping of polyamide or wool fibres. Reactive dyes inwards the simplest terms, all reactive dyes are made upward of 3 basic units, a chromophore, a span as well as a reactive group/ groups (either a haloheterocycle or an activated double bond). One occupation is that instead of reacting alongside the -OH groups on the cellulose, the fibre-reactive grouping may react alongside the HO- ions inwards the alkali solution as well as instruct hydrolysed. The hydrolysed dye cannot react further. This must last washed out of the cloth earlier use.

2.2 Properties of Reactive Dye:

Reactive dyes are anionic dyes, which are used for dyeing cellulose, poly peptide as well as polyamide fibres.
Reactive dyes are industrial plant life inwards power, liquid as well as impress glue form.
During dyeing the reactive grouping of this dye forms covalent bond alongside fibre polymer as well as becomes an integral part of the fibre.
Reactive dyes are soluble inwards water.
They conduct maintain really adept lite fastness alongside rating almost 6. The dyes conduct maintain really stable electron organization as well as tin sack protect the degrading outcome of ultra-violet ray.
Textile materials dyed alongside reactive dyes conduct maintain really adept launder fastness alongside rating Reactive dye gives brighter shades as well as conduct maintain moderate rubbing fastness.
Dyeing method of reactive dyes is easy. It requires less fourth dimension as well as coldness for dyeing.
Reactive dyes are comparatively cheap.
Reactive dyes conduct maintain adept perspiration fastness alongside rating 4-5.
Reactive dyes conduct maintain adept perspiration fastness.

2.3 The Components of Reactive Dye

Figure: 2.1. Typical Components of a Reactive Dye

a) The chromogen:
Dye part or chromogen (color producing part), which contains chromophores. Chromophore - a color-bearing compound, typically pregnant the part of a larger organic molecule that makes it look colored. Some chemicals groups which are responsible for the impart color to the substrate. Dyes typically conduct maintain a chromophore chemically bonded to other structures that impart desired characteristics such equally affinity for the fibre as well as solubility inwards water. Influenza A virus subtype H5N1 item chromophore construction may last industrial plant life inwards a diversity of dye classes as well as inwards pigments. In practice, monoazo, disazo, metallized monoazo, metallized disazo, formazan, anthraquinone, triphenodioxazine, as well as phthalocyanine chromophores conduct maintain been used for the training of reactive dyes.

b) The H2O solubilising grouping (ionic groups, frequently sulphonate salts):
The groups which conduct maintain the expected outcome of improving the solubility since reactive dyes must last inwards solution for application to fibres. This agency that reactive dyes are non dissimilar acid dyes inwards nature. Solubilizing groups render characteristics such equally H2O solubility, substantivity, migration as well as launder off. The dominant solubilizing grouping inwards reactive dyes is the sulphonic substituent.

c) The bridging group:
It links the chromogen as well as the fibre-reactive groups. Frequently the bridging grouping is an amino, -NH- grouping or –NR- group. This is normally for convenience rather than for whatever specific purpose as well as they too influence the reactivity, marking of fixation, stability of the reactive dyeing as well as other dyeing characteristics, such equally substantivity as well as migration, significantly. The typical bridging grouping is an imino (-NH-) group.

iv) The fibre-reactive group
This is the entirely part of the molecule able to react alongside the fibre. Reactive grouping do non contribute color which is determined past times chromogen group. The reactivity of vinyl sulphone grouping is less than element of group VII group. If no of reactive grouping incresase, binding too increment depending on the dye structure. If the molecular weight of reactive grouping increases, reactivity too increases.

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