Spectral and thermal analysis of Eucalyptus wood drying at different temperature and methods

In order to better understand the chemical changes after wood drying, Eucalyptus wood was dried to an absolutely dry state following the five types of treatment: oven-dried at 60, 90, 120, and 150 °C, and vacuum freeze-dried. The tangential shrinkage rate (β) of oven-dried specimens was increased from 7.63 to 9.90% as treatment temperature was increased, and the β of the specimen submitted to vacuum freeze drying was 7.40%, scoring close to the specimen oven-dried at 60 °C. The chemical characteristics and thermogravimetric analysis of the specimens were studied based on the drying results. Here, the results confirmed that vacuum freeze drying has little effect on the chemical composition of wood and showed that, for oven-dried samples, the chemical composition of wood varies with the drying temperature. Concerning crystallinity of the oven-dried specimens, it was decreased from 38.57 to 26.22% as the treatment temperature was incremented. In turn, the crystallinity of the specimen processed with vacuum freeze drying was the lowest one.