Effect of Coconut Shell Powder as Filler on the Mechanical Properties of Coir-polyester Composites

Abstract

Coir mat was used as reinforcement, polyester resin was used as matrix and coconut shell powder (CSP) was used as filler material which was employed as 10, 20, 30, 40, 50, 60 and 100% by weight in the composites. Coir mat/polyester resin composites were made by hand lay-up technique. Mechanical properties such as tensile strength (TS), bending strength (BS), tensile modulus (TM), bending modulus (BM), elongation at break and impact strength (IS) were also investigated. The maximum increase of TS, BS, TM, BM and IS were found to be 44.44, 128.00, 17.96, 112.09 and 62.50% respectively for 30% filler content on the composites. It was revealed that the strength properties of the composites were increased with the increase in filler content up to 30% by weight, however, further increase in filler content the value decreased. Gamma radiation of 100, 250 and 300 krad doses were applied on 30, 40 and 60% filler content composites. Gamma radiation dose of 250 krad showed better result than that of other doses. IS of the composites improved 48.08, 26.67 and 17.50% for 30, 40 and 60% filler content respectively at 250 krad, where 30% filler content composites displayed the highest improvement. Degradation tests of the composites for up to 50 days were performed in a soil medium. It was revealed that BS decreased for all the composites.