14. Experimental investigation of the effects of fiber size on mechanical properties of styrene based wood-plastic composites

摘要

Although numerous wood-plastic composites (WPC) utilize Polyethylene (PE), Polypropylene (PP), and Polyvinyl Chloride (PVC), very little literature exists specifically applying to styrene based compounds like Acrylonitrile Styrene Acrylate (ASA) and Styrene Block Copolymers (SBC). Torque rheometry was used characterize the wood filled ASA and SBC and ascertain the temperatures necessary for steady-state torque. Test mixtures were formulated with 60 mesh wood fiber at 40%, 50%, and 60% in three separate polymers. The mixtures were extruded on a twin-screw extruder in sample bars for flexure and water soak testing. Preliminary testing indicated the ASA polymer and one of the SBC polymers were viable candidates for further testing at 50% and 60% wood fiber. Both 100 mesh and 140 mesh pine wood fibers, at comparable 50% and 60% levels, were then used to determine the effects of particle size on mechanical properties and water sorption performance within the ASA and SBC polymer matrices. Tests currently in progress focus on the addition of SBC to ASA to raise MOR and strain at break, and experimentation with alternate material fibers for further improvement of mechanical properties.