Chitosan, a versatile biopolymer, finds numerous applications in textile processing unit operations such as preparation, dyeing, printing, and finishing. However, the accessibility of this biopolymer by the textile material depends on the viscosity of its solution which in turn is a function of its molecular weight. In this work, therefore, the effect of molecular weight, storage life, presence of electrolyte, and particle size of chitosan on its viscosity was investigated. Chitosan of different molecular weights was synthesized by nitrous acid hydrolysis of parent chitosan solution. The synthesized low molecular weight products were analysed by FTIR spectroscopy. Chitosan of nanoconfiguration was prepared by Ionotropic gelation method and characterized by particle size analyzer. The viscosity of different chitosan solutions was determined using Ubbelohde capillary viscometer. As an extension to this study, the chelation property of chitosan was also evaluated.

The graft copolymerization of acrylic acid onto isotactic polypropylene has been investigated. The grafting was carried out using benzoyl peroxide initiator. Grafting is essentially a surface phenomenon and takes place, mostly, in amorphous region of the fiber. Emphasis, therefore, was placed on various pretreatment techniques for swelling of the fiber, viz, pretreatment with toluene and 1,1 0 2,2 0 tetrachloroethane, ultrasound, and photoirradiation. Process parameters, characterization study such as IR spectroscopy, TGA, and DTA, and properties such as tensile properties, melting temperature, dyeability towards basic dyes, and ion exchange properties were investigated. Benzene was found to be the most suitable solvent for initiator as against the acetone. Tenacity was found to be increased with increase in graft yield and reached to maximum at about 5% graft add-on, and then decreased with further increase in graft add-on. Proportionally, a converse effect was reported in the study of elongation to break. Thermal stability of polypropylene was found to be improved because of grafting. The grafted polypropylene also showed satisfactory dyeability toward basic dyes and also exhibits very good ion exchange properties.

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