Study of the Structural and Mechanical Properties of Recycled High Density Polyethylene/Palm Kernel Shell Ash Bio-Composite

Abstract

This study examined the structure and mechanical properties of recycled high density polyethylene(RHDPE)/palm kernel shell ash (PKSA) bio-composite. The reinforcement was added to the polymer matrix in concentrations of 5, 10, 15, 20 and 25wt% and particle sizes of 100, 150, 200, 250, 300µm. The composite samples were produced using injection moulding technique and subjected to mechanical and tribological property tests for percentage elongation, ultimate tensile strength, and hardness. The structure of the composite samples was analyzed using an optical metallurgical microscope. Results of the structural analysis revealed that the reinforcement of small particle size (100µm) formed a better interfacial bond with the polymer matrix compared with that of other particles sizes. The structural analysis also revealed uniform distribution of hard and brittle particles of the reinforcement in the polymer matrix. Mechanical test results showed that addition of palm kernel shell ash to the polymer matrix decreased its percentage elongation and impact strength by 24.5% and 22% respectively but significantly increased the tensile strength and hardness by 107.9% and 72% respectively. The ultimate tensile strength, and hardness of the developed composite increased with decrease in reinforcement particle size. Maximum ultimate tensile strength of 131MPa was obtained by the RHDP containing 10wt% PKSA of 100µm particle size while maximum hardness value of 86BHN was obtained at 25wt% palm kernel shell ash of 100µm particle size addition. Palm kernel shell ash reinforced recycled high density polyethylene bio-composite of improved mechanical properties that can be applied in production of engineering components. Keywords: Palm kernel shell ash, RHDPE, Percentage elongation, Ultimate tensile strength, Hardness. DOI : 10.7176/CPER/62-05 Publication date: January 31 st 2020