On the development of natural fiber composites of high-temperature thermoplastic polymers

A new method is presented for the development of natural fiber composites of high-performance thermoplastic polymers considering poly(phenylene ether) (PPE) and wood flour as an example system. The large gap between the high processing temperature of PPE, typically between 280 and 320degreesC, and the low decomposition temperature of wood flour, about 200degreesC, was reduced by using a reactive solvent, a low molecular weight epoxy. The epoxy formed miscible blends with PPE, which offered much lower viscosity compared to PPE and processing temperatures well below the decomposition temperature of wood flour. In addition, the epoxy component accumulated around the polar wood flour particles upon polymerization during the fabrication step. The composite materials consisted of a thermoplastic continuous phase and two dispersed phases, one of polymerized epoxy and the other of wood flour particles coated with polymerized epoxy. These composites offered a significant reduction in density and better mechanical and physical properties when compared to commercially available grades of engineering polymer blends filled with short glass fibers. (C) 2002 Wiley Periodicals, Inc.