Wood composites with enhanced dimensional stability and decay resistance fabricated by in-situ curing of waterborne epoxy resin containing tertiary amine cation

As one of the most important renewable and multifunctional natural resources, wood has been widely used in various industrial fields like indoor decoration and construction engineering, yet wider applications of woody materials are significantly hampered by the inherent wood defects of dimensional instability and susceptibility to fungal attack. In this work, an environmentally friendly wood modification approach free of volatile organic solvents was proposed and the wood composite material with simultaneous enhancement in dimensional stability, strength and decay resistance was prepared. The nano-scaled WEP containing tertiary amine cation, which was prepared by a simple three-step chemical modification, exhibited good stability and great ease of uniform impregnation into wood porous structures like cell lumens and cell walls. The size of wood vessel and cell cavities was decreased as investigated by SEM measurement, and the hardness and modulus for wood cell walls measured by nanoindentation were found to increase. Also the flexural, tensile and compressive performance of wood composites were enhanced. In addition, wood composites after 90-day decay tests against white and brown rot fungi presented relatively low mass loss rates of 8.1 % and 2.0 % and no visible change in shape could be observed, indicating attainment of a strong decay resistance.