PROPERTY ENHANCEMENT AND OPTIMIZATION OF POLYPROPYLENE MATRIX FOR AUTOMOBILE APPLICATION: INFLUENCE OF COIR FIBER PROPORTION AND LENGTH

Abstract

Coir-polypropylene composite was developed by the addition of coir fiber treated with 1.7 M NaOH solution for 24 hours at fiber loading 0 – 30 wt. % for automobile application. The fibers were cut to different length of 20 -50mm. Samples produced were subjected to test to examine tensile and flexural strengths and moduli, impact strength and hardness. Microstructural analysis was also carried out. Results obtained reveal rise in tensile strength with increasing fiber proportion up to 15 wt. % before a decline down to 30 wt. %. Increasing fiber length was observed to contribute to appreciation in strength up to 40 mm. Tensile modulus (TM) trended upward with in increased fiber loading up to 30 wt. % for length from 20 to 40 mm and for fiber cut to 50 mm, TM appreciated up to 15 wt. % before eventual depreciation. Results of flexural strength and modulus showed that flexural strength rose with increasing fiber loading up to 30 wt. % for coir fibers cut to 20 to 40 mm. Coir cut to 50 mm, gave increase up to 15 wt. % before eventual decrease in value. Flexural modulus rose from 0 to 30 wt. % for all fiber length except when 50 mm length was incorporated into the composite resulting lower modulus when compared with the ones recorded for coir of 40 mm length.