The effect of filler loading and coupling agent on properties of bentonite filled recycled high density polyethylene composites

Abstract

Recycled high density polyethylene/ bentonite (RHDPE/Bentonite) composites had been prepared using Brabender Plasticorder at temperature 160˚C and rotor speed of 50 rpm. The effect of Bentonite loading and coupling agent on tensile properties, swelling behavior, morphology analysis, and spectroscopy infrared (FTIR) analysis on RHDPE/Bentonite composites were studied. The result showed that the addition of Bentonite reduced the tensile strength, elongation at break and weight swell percentage of composites, whereas the Young’s modulus increased. Coupling agent such as polyethylene graft maleic anhydride (PEgMAH) and maleic anhydride (MAH) were used, which resulted in positive effect on mechanical properties, and reduce the weight swelling percentage of RHDPE/Bentonite composites. The RHDPE/Bentonite/PEgMAH composites have higher tensile strength, Young’s modulus, and elongation at break but lower weight swell percentage compared to the RHDPE/Bentonite/MAH composites. The scanning electron microscopy (SEM) micrographs of tensile fractured surfaces for the RHDPE/Bentonite composites with coupling agents of PEgMAH and MAH indicated that the interfacial adhesion between Bentonite and RHDPE composites were better than the RHDPE/Bentonite composites without the coupling agents.