Effects of material parameters on the diffusion and sorption properties of wood‐flour/polypropylene composites

Abstract

Composites of wood in a thermoplastic matrix (wood-plastic composites) are considered a low maintenance solution to using wood in outdoor applications. Knowledge of moisture uptake and transport properties would be useful in estimating moisture-related effects such as fungal attack and loss of mechanical strength. Our objectives were to determine how material parameters and their interactions affect the moisture uptake and transport properties of injection-molded composites of wood-flour and polypropylene and to compare two different methods of measuring moisture uptake and transport. A two-level, full-factorial design was used to investigate the effects and interactions of wood-flour content, wood-flour particle size, coupling agent, and surface removal on moisture uptake and transport of the composites. Sorption and diffusion experiments were performed at 208C and 65 or 85% relative humidity as well as in water, and diffusion coefficients were determined. The wood-flour content had the largest influence of all parameters on moisture uptake and transport properties. Many significant interactions between the variables were also found. The interaction between wood-flour content and surface treatment was often the largest. The diffusion coefficients derived from the diffusion experiments were different from those derived from the sorption experiments, suggesting that different mechanisms occur.

DNA‐PKcs‐dependent NHEJ pathway supports the progression of topoisomerase II poison‐induced chromosome aberrant cells

“…In our study, wood content in the WPCs is the most important factor which affects the rate of water absorption. This is consistent with the work done by Steckel et al [24]. When wood content of WPCs increased from 50 wt% to 52 wt%, the rate of water absorption of WPCs increased by a factor of 1.25.…”

Effect of Durability Treatment on Moisture Sorption Properties of Wood-Plastic Composites

“…WPCs can be detrimentally affected by the presence of excess water. Dynamic water absorption within the composites is intrinsically related to the degradation process (Tsenoglou et al 2006;Steckle et al 2007). Thus, understanding the water absorption process in WPCs is very important for the prediction of their application behaviors in highly humid environments (Chen and Shaler 2010).…”

Resistance of modified polyvinyl chloride/wood flour composites to basidiomycetes

“…In general it is said that wood species with higher durability are also causing higher durability of the composite (Stokke and Gardner 2003;Fabiyi et al 2011;Kim et al 2008). In contrast to solid wood, water uptake, water diffusion and water release is obviously reduced in WPC (Steckel et al 2007;Chen et al 2006). Thus, water pre-treatment of the samples is necessary to obtain suitable moisture contents for fungal decay and to create worst condition for the composite (Defoirdt et al 2010;Rowell 2007;Kim et al 2008Kim et al , 2009.…”