The durability of two sets of Wood-Plastic Composites (WPCs), one based on polypropylene (PP) another on high-density polyethylene (HDPE) was investigated. Injection molded samples of the WPCs with different loadings of wood fiber ranging from 0 to 36 wt. percent of wood were subjected to laboratory accelerated weathering as well as natural weathering under harsh desert exposure conditions in Dhahran, Saudi Arabia. The integrity of samples weathered to different extents were tested using standard tensile test and surface hardness test to investigate the dependence of these properties on the duration of weathering exposure. The average tensile strength of all composites as well the respective controls decreased monotonously with weathering exposures. Their tensile moduli increased with weathering indicating extensive crosslinking and possible increased crystallization during the weathering exposure. Changes in hardness with exposure also indicated a similar decrease under both exposure regimens. The changes obtained compare well with those reported for WPCs using a different wood fiber. An interesting correlation between hardness and tensile properties was obtained for PP-based composites.
Halim Hamid Redhwi, Chemical Engineering Department
King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
International Union of Photobiology (IUPB), the Molecular and Experimental Pathology Society of Australasia (MEPSA) World Congress 2024