Influence of Poly(Vinyl Butyral) on the Dynamic-Mechanical and Mechanical Properties of Polypropylene/Wood Flour Composites

This study reports the influence of recycled poly (vinyl butyral) (PVB) in dynamic mechanical and mechanical properties of polypropylene (PP)/wood flour composites prepared in a twin screw extruder. After extrusion, the PP/wood flour composites were injection molded to obtain specimens for tensile, flexural, impact and dynamic mechanical (DMA) tests. The morphology of the composites was analyzed by scanning electron microscopy (SEM). The addition 10 wt% of PVB in PP/wood flour composite reduced from 5°C to-10°C the β transition (glass transition) peak temperature of the loss modulus. In a temperature range between 40°C and 100°C the composites containing PVB presented the highest peak in the loss modulus. The most intense tan delta peaks between 50°C and 100°C for composites containing PVB were attributed to the combined effects of PP α transition with the PVB glass transition temperature. The PP/wood flour composites with PVB presented a tendency to increase the absorbed energy by impact.