Effect of brown rot fungus on the functional characteristics of heat treated wood

The purpose of this study was to investigate the effect of heat treatment on biological resistance and some physical and mechanical properties of paulownia wood (Paulownia fortunei). Thermo-wood specimens were prepared from paulownia wood based on thermo-D process. Heat-treated and untreated wood specimens were evaluated after exposing to brown rot fungus for 16 weeks. The laccase activity and its effect on mass loss and wood density were investigated. Moreover, some mechanical properties including impact strength and compression parallel to grain was measured. Evaluation of laccase activity showed more efficiency of this enzyme in untreated specimens in compared with thermo-wood and also it resulted in more mass loss. Therefore, heat treatment can improve biological resistance. The results also showed that heat treatment reduces density and impact strength of specimens, but improve compression parallel to the grain. Investigation of physical and mechanical properties of specimens exposed to brown rot fungus also showed that heat treatment reduced efficiency of this fungus on paulownia wood. So that, the value of mass loss, density and compression parallel to the grain in controls were more than thermo-wood. However, reduction of impact strength of thermo-wood was more than controls.