Preparation and Characterization of Heat-Treated Douglas Fir Wood with Core–Shell Structure

Wood heat treatment has been generally accepted as an effective wood modification technology it improves the dimensional stability and biological durability of wood. However, property improvements are obtained at cost reduced mechanical properties. In this study, heat-treated Douglas fir with thermally modified shell unchanged inner core was prepared by surface heating to make possible broader applications Colour comparison, dynamic vapor sorption analysis were performed characterize physico-mechanical performance treated The results reveal a darkened, hydrophobic rigid barely changed core. X-ray photoelectron spectroscopy shows pronounced degradation polysaccharides in layer. contrast, relative contents different carbon components layer similar that untreated wood, indicating reason for difference between initial moisture content plays important role controlling temperature gap during can be used key parameter adjust structure