The purpose of this study was to clarified the mechanism of dimensional stabilization of wood treated with azelaic acid. In this study, the effects of heating temperature of azelaic acid treatment on the weight percent gain, the bulking, and the hygroscopicity of treated wood were investigated in detail. Furthermore, the effects of heating temperature on the reaction between azelaic acid and wood components were also investigated, and the mechanism of dimensional stabilization at each heating temperature was considered. The bulking of treated wood was almost constant at heating temperature in the range of 70-80°C, increased with the temperature in the range of 90-130°C, and was almost constant in the range of 130-150°C. The swelling of treated wood by moisture absorption was almost constant in the 70-80°C range, decreased with the temperature in the range of 90-130°C, and increased with the temperature in the range of 130-150°C. The moisture content of treated wood after absorption was almost constant in the range of 70-100°C, and decreased with the temperature in the range of 110-150°C. When the IR spectra of treated wood heated at 90°C and 130°C were compared, it was clarified that the azelaic acid and the wood were esterified at 130°C. It was suggested that this reaction was contributed to the decrease of moisture content of treated wood. The bulking of treated wood was significantly contributed to dimensional stabilization from 70°C to 130°C, and it was suggested that there were factors other than the bulking that slightly decreased dimensional stability from 130°C to 150°C.
