Effects of chemical modification on the mechanical properties of wood

Chemical modification has been recognized as an efficient strategy for dimensionally stabilizing wood and protecting it from environmental damage, such as deterioration due to weathering and fungal decay during the service period. Studies reported in the literature mainly concern the establishment of workable modification techniques, testing methodologies, and assessment of the durability of modified wood. The development of wood modification techniques has recently been reviewed; limited information is however given on the effects of chemical modification on the mechanical properties of wood that are of importance to it as an engineering material. This paper reviews the effects of wood modification, typically by heat treatments and impregnation with low molecular weight resins, reactive monomers, or hot melting paraffins on the mechanical properties of wood. The modifying variables associated with mechanical properties of wood such as wood species, treating temperature and time, catalyst, type of solvent, weight percent gain, and molecular structures of the modifying agent were analysed and the results interpreted. The reasons for changes in the mechanical properties of wood are discussed.