Water absorption and its effect on mechanical properties of hybrid wood particulates composites

The hydrophilicity/hygroscopicity of wood particle reinforced epoxy composites offer the degradation in its mechanical properties, and also restricts these composites for outdoor or moisture changing environmental applications. The present work aims at experimental investigations of water uptake behaviour of hybrid softwood/hardwood particle reinforced epoxy composite and its effect on the mechanical properties. The hybrid pinus (softwood or SWP) and shorea robusta (Hardwood or HWP) epoxy composites are prepared keeping constant 25 wt% as total amount of reinforcement with varying ratio of wood particulates. The water absorption analysis includes determination of percentage water-soaked; sorption, diffusion and permeability coefficients of hybrid composites. The tensile, flexural and impact tests are conducted on water-soaked samples to study the effects of water absorption. The SEM morphology of water-soaked samples under different mode of loadings is also presented. The water resistance capacity and lowering in the mechanical degradation by water absorption of wood composites are found to enhance by hybridization of pinus and shorea robusta wood particulates. (paper)