Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Abstract:
This paper is aimed at investigating the suitability of de-structured (or pre-gelatinized) starch for the enhancement of the biodegradability of polypropylene plastic. The starch was extracted from sweet potato and was further enhanced by pre-gelatinization. Blends of the starch and polypropylene plastic pellets were obtained, casts and dried into three starch-filled polypropylene plastic slab samples, graded on the basis of 10, 20 and 30 % starch composition. These samples were subjected to biodegradation tests for a 90-day study period by disposing them into sea water and salt solution environments. There was no any traceable biodegradation of the starch-filled polypropylene plastic samples in salt solution except in the sea water. The optimum rate of biodegradation of 0.015 g/g day showed by the 10 % starch-filled polypropylene plastic sample in sea water environment is an indication that 10 % starch constituent is adequate for polypropylene plastic biodegradation. The formulated regression models on the dependence of rate of biodegradation on sea water temperature and plastic slab thickness also showed better correlation in the 10 % starch-filled polypropylene plastic slab sample than the others. Its R2 and SE were 0.986 and 0.06 respectively.

Keywords: starch, polypropylene plastic, biodegradation rate, sea water environment, regression models.

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