visit us at www.intertechusa.com Effect of Species and Particle Size on Properties of Wood-Flour-Filled Polypropylene Composites

Wisconsin. This article was written and prepared by U.S. Government employees on official time, and it is therefore in the public domain and not subject to copyright. The use of trade or firm names in this publication is for reader information and does not imply endorsement by the U.S. Department of Agriculture of any product or service. Research on wood-flour-filled polypropylene has primarily focused on one species of wood flour and one or two broad particle-size distributions. To fully exploit the use of wood flour as a filler, the effects of species and particle size need to be examined. This study focused on the effects of both of these variables on the properties of polypropylene filled with wood flour. To examine the effects of species, wood flour derived from four species, ponderosa pine, loblolly pine, maple, and oak, was used as a filler for polypropylene at 20,30,40,50, and 60 % by weight wood flour. With increasing wood flour content, flexural and tensile modulus, density, heat deflection temperature, and notched impact energy increased, while flexural and tensile strength, tensile elongation, mold shrinkage, melt flow index, and unnotched impact energy decreased. In general, the hardwoods exhibited slightly bette