Influence of Compatibilizers and Processing Temperature on Microcellular Injection-Molded PoIypropylene/(Waste Tire Powder) Composites

摘要

Nowadays the economic recycling of waste tires has become a global challenge. The use of waste tire powder as a dispersed elastomeric phase in a polypropylene (PP) matrix offers an interesting opportunity for recycling of waste tire rubber. Compatibilized PP/(waste tire powder) composites are microcellu-larly processed to create a new class of materials with unique properties. Recent studies have demonstrated the feasibility of developing microcellular structures in PP/waste ground rubber tire (WGRT) composites. Microcellular PP/WGRT composites are prepared by an injection-molding process using a chemical blowing agent. In this study, cell sizes, cell density, void fraction, and mechanical properties of the composite foams were measured, as well as the shear viscosity of the unfoamed composites. The influence of various compatibilizers and processing temperatures on cell morphology and the mechanical properties of Injection-molded PP/WGRT composites were investigated. It was seen that the addition of maleic anhydride-grafted styrene-ethylene-butyl-ene-styrene (SEBS-g-MA) increased the shear viscosity of the composites. The void fraction and cell density of the PP/WGRT composites increased with addition of compatibilizers, whereas the average cell sizes decreased. A processing temperature range of 180~(-1)95 C gave finer microcellular structure and regular cell distribution. The SEBS-g-MA enhanced the elongation properties and acted as an effective com-patibilizer in this particular system.