Effects of Environmental Aging on The Durability of Wood-Flour Filled Recycled PET/PA6 Wood Plastic Composites

Abstract

\n Outdoor building materials made of wood require preservatives containing chromated copper arsenate and other carcinogenic substances but still are subject to decay, hence they need to be replaced every few years. Wood plastic composite (WPC) is a novel environmental-friendly composite of wood flour/fiber reinforced thermoplastic polymers (i.e. plastic). As WPC is made of plastic to evenly cover the wood flour, it has a lower moisture content than wood. In this study, maleic anhydride grafted polyolefin (POE-g-ma) and methyl metharylate-butadiene-styrene copolymer (MBS) were used as impact modifiers to prepare recycled WPCs (rWPCs) from recycled polyethylene terephthalate (rPET) and recycled polyamide 6 (rPA6) blends (PET/PA6). The thermal properties of the WPCs with different mixing ratio polymer blends of rPET to rPA6 (E60/A40, E50/A50, and E40/A60) were investigated, as well as their mechanical properties after accelerated weathering. Furthermore, the creep property of rWPC was also investigated under different applied loading and environmental aging conditions. The higher PET content resulted in lower flowability and a higher initial decomposition temperature, with the E60/A40 rWPC having better mechanical properties. During the 10-hour creep test, the rWPC strain changed significantly with environmental aging and higher loadings. In conclusion, the rWPC composed of 60:40 PET to PA6 is more suitable for outdoor building applications.