The Influence of a Thermal Treatment on the Decay Resistance of Wood via FTIR Analysis

The decay resistance of wood can be improved via a vacuum heat treatment. The amount of nutrients from cellulose, hemicellulose, and lignin and amount of sugars needed by the fungi during their growth were investigated. The results showed that the absorbance peaks corresponding to absorbed CH3-CH2-, C=O, and the benzene ring skeleton stretching vibration all noticeably weakened with increased heat treatment. This indicated that the cellulose, hemicellulose, and lignin degraded to varying degrees. The specimens with a higher initial moisture content (MC) showed greater amounts of nutrient degradation after 2 h at the same heat treatment temperature. The chemical analysis results were in good agreement with the Fourier transform infrared (FTIR) analysis results. The decay resistance tests showed that the average mass loss of the heat-treated specimens was up to 10.8%, in contrast to 22.23% for the untreated specimens. Furthermore, the FTIR analysis of the heat and decay-resistance test showed that the vibration wave peaks that corresponded to CH3-CH2- at 2954 cm−1 showed noticeably less separation at higher heating temperature. This demonstrated that the cellulose hydrolysis in the wood decreased at higher heating temperatures, which explained why the decay resistance increased with increased heat treatment.