Effects of wood fiber properties on mold resistance of wood polypropylene composites

Abstract

This study investigated the effects of mold susceptibility, total soluble sugar contents and chemical components of wood fibers on mold resistance of wood-polypropylene composites (WPC) filled with white poplar, moso-bamboo, Chinese fir, Ramin, white pine, red gum, red cedar, and rubberwood. Susceptibilities and resistances to molds were studied by artificially accelerated tests. The total soluble sugar contents and chemical components of wood fibers were analyzed by anthrone colorimetry and gas chromatography-mass spectrometry (GC-MS), respectively. Experimental results showed that the mold resistance of WPC varied significantly with wood fiber species. Higher natural durability of wood fiber resulted in higher mold resistance of WPC, while higher sugar contents decreased the resistance of WPC against molds. Low initial moisture content did not have any influence on the susceptibility of WPC towards fungal attack, but higher final moisture content was the result of heavy mold growth on WPC. GC-MS analysis suggested that different chemical components of wood fiber species affected the mold resistance of WPC either positively or negatively. This study provides an alternative solution to improve the durability of WPC against fungal attack.