CREEP RUPTURE OF A TROPICAL WOOD POLYMER COMPOSITE.

Abstract

Wood polymer composite (WPC) specimens were produced by impregnating a tropical wood with methyl methacrylate (MMA) and subsequently polymerized by gamma irradiation. Beam specimens of varying weight percentages of polymer were then subjected to three-point-bend creep rupture test under a constant load condition. Results indicated that the impregnation of MMA and subsequent polymerization by irradiation to form WPC significantly increased the creep rupture resistance of the wood. Two models, namely, a three element non-linear mechanical model derived from an energy failure criterion and a power law model derived from a damage parameter concept, modelled adequately the creep rupture time of the WPC. Results indicated that the equation parameters increase significantly in the first 20 or 30% polymer loading in agreement with previous work. An interfacial interaction between the polymer and the wood cell wall was used to account for the behavior of the increase in the creep rupture resistance.