Preparation and mechanical failure analysis of wood-epoxy polymer composites with excellent mechanical performances

In this study, wood-epoxy polymer composites (WEPC) with excellent mechanical properties were prepared by adjusting the stress–strain system under mechanical load after introducing epoxy monomers into the cell cavities of plantation wood. The flexural strength, modulus, compression strength, and impact strength of the WEPCs were improved by up to 110.3%, 86.5%, 137.3%, and 110.6%, respectively. The flexure strength (140.5 MPa) was far beyond strength class TB20 (98 MPa), which was higher than that of rosewood. The improvement in mechanical strength was mainly attributed to the change of stress concentration properties by sharing the load with the epoxy polymer and the enhanced cell walls. The enhanced toughness was attributed to the increase in longitudinal cell splitting, as well as the "propagation of cracks" and "debonding" among multilevel structures of cell walls. The mechanical failure mechanism of WEPCs can be used as a reference for the design of wood-based composites.