Gamma degradation studies of chitosan and sodium alginate biopolymers

Abstract

Various biopolymers have been reported to play very important roles in different fields including pharmaceutical sciences, water treatment as well as nanosciences. The properties of these biopolymers are widely affected by their molecular weight, structural and functional moieties on them. In order to improve the efficiency towards desired application, they are subjected to chemical and physical processes. One of them is radiation induced degradation or crosslinking. Radiation has been reported as one of the methods for modification of polysaccharides. In this study, chitosan and sodium alginate have been degraded using gamma radiation from 60Co source with dose rate of 4.295 kGy/h, with doses upto100 kGy. The molecular weights have been determined by viscosity method. Similarly, both have been subjected to various characterization methods such as TGA-DTA, XRD, FTIR, SEM-EDX, UV-Vis and DDA (degree of deacetylation). Radiation induced degradation is confirmed through reduction in molecular weight with respect to gamma dose. Basic advantage of radiation degradation of biopolymers includes ability to promote changes in a reproducible manner, quantitatively and without introduction of chemical agents. The highlight of gamma irradiation of biopolymer is that there is no chemical waste generation.