Production of Wood/Plastic Composites Based on PP/HDPE Blends: Determination of Optimum Conditions
Mechanical properties of wood/plastic composites manufactured by polyethylene and polypropylene blends (PP/HDPE) were studied. The SEBS (styrene-ethylene butylene-styrene) and EPDM (ethylene-propylene diene monomer) were used as compatibilizers to improve the compatibility and miscibility of the interface between HDPE and PP phases. The sawdust and polymers were compounded using an internal mixer (Haake). The samples of wood/plastic composite were prepared by injection-molding. Mechanical properties of wood/plastic composites such as, flexural modulus and flexural strength, impact strength and tensile strength were determined. The Taguchi method was employed in order to optimize these properties. Blends of PP and PE (3 levels), MAPP content (3 levels), polymer compatibilizer content (3 levels), polymer compatibilizer (two types) were considered as variable parameters. The results indicated that wood/plastic composites containing: 80% HDPE with 20% PP blend, 4% MAPP coupling agent, 2% polymer and EPDM compatibilizers were the optimum conditions to acquire the best quality composites. The fracture surfaces of samples were observed by scanning electron microscopy.