Effect of Biodegradation on Thermal and Crystalline Behavior of Polypropylene-Gelatin Based Copolymers

Gelatin-based graft copolymers of polypropylene (PP), has been synthesized by chemical method using benzoyl peroxide (BPO), as radical initiator. Biodegradation studies of pristine PP and PP-g-Gelatin have been carried out by soil burial test in simple soil and soil enriched with nitrogenous content by adding urea. The microbial degradation was substantiated by the direct attack of the microbes on the grafted samples. The rate of degradation by the direct attack was fast in comparison to the degradation in soil burial studies. The biochemical tests performed on the organisms isolated from the soil, identified these organisms as Bacillus circulans, Kurthia gibsonii, and Flavobacterium sp. which helped biodegradation of PP-g-Gelatin samples. The degradation of the grafted samples was further confirmed by carrying out the physical characterization of the original samples and the degraded samples by SEM, XRD, and TGA. The XRD and thermal data indicate an increase in the crystallinity of the degraded samples. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 1476-1488, 2010