Optimization of processing parameters and its effect on the mechanical properties of recycled low density polyethylene composite reinforced with Tetracarpidium conophorum shell particulates

Abstract

This work explored the effect of African Walnut Shell Particle (AWSP) (Tetracarpidium conophorum) on the properties of recycled low density polyethylene (rLDPE) composite. rLDPE/ AWSP composite were prepared via compressive moulding techniques using AWSP of sizes 300 and 600μm respectively. Composite design of experiment and analysis of variant (ANOVA) were employed for optimization. Mechanical and morphological analysis of the composite were studied. rLDPE reinforced with AWSP of particle size 300 μm exhibited better tensile strength, modulus of rupture (MOR) and modulus of elasticity (MOE) than those of 600 μm. Morphological analysis showed that uniform distribution of the Walnut shell particulates in the microstructure of the composite is the major factor responsible for the improvement in the mechanical properties. Optimality occurred at a press temperature of 206.465 °C, press time of 10 min, press pressure of 7 MPa yielding a tensile strength of 14.082 MPa, MOR of 17.019 MPa and MOE of 755.028 MPa for 300 μm particle sized composite whereas for 600 μm size, it was achieved at press temperature of 199.993 °C, press time of 6 min, press pressure of 7 MPa giving a tensile strength of 11.252 MPa, MOR of 15.401 MPa and MOE of 459.531 MPa respectively. The result from the optimization met the standard for interior and exterior mirror casing of automobiles.