Response of hygroscopicity to heat treatment and its relation to durability of thermally modified wood

In an attempt to study the effect of heat treatment on hygroscopicity and durability of wood, Poplar (Populus spp.) wood was thermally modified using five different temperatures between 170 °C and 210 °C, for a fixed duration of 3 h. Moisture adsorption behavior and the resistance to soft rot fungi were investigated thereafter. Based on the Hailwood-Horrobin sorption model, the amount of available sorption sites within specimens for the different groups of Poplar wood were calculated from the model's m0 parameter. Chemical analysis of the changes in wood components induced by heat treatment allows for a comparison between the easily obtained m0 and the results of time-consuming wood decay tests. The proposed m0-based method for highly efficient evaluation and prediction of durability of thermally modified wood could optimize future research on the mechanisms of heat treatment processes.