Abstract

The chemistry of chitosan together with some aspects of its applications have been reviewed. The shrinkage temperature of hide powder was found to be increased by treatment with the polyaminosaccharide which may be due either to the formation of cross-links between the polymer and the hide fibre or the physical presence of the high molecular weight polymer within the substrate. The rate and extent of uptake of C.I. Acid Yellow 83 onto chrome tanned hide powder were increased by means of pretreatment with chitosan as a result of the provision, by the cationic polymer, of additional dye sites within the substrate. Enhancement of dye uptake was greater when pretreatment had been carried out prior to chrome tanning which may be attributable to chelation of chromium by the polyaminosaccharide. The perspiration fastness of C.I. Acid Red 249 on lightly retanned leather was increased by means of an aftertreatment with chitosan which can be attributed to the formation of an insoluble, large molecular size, dye-chitosan complex.