Structural characterization of steam-heat treated Tectona grandis wood analyzed by FT-IR and 2D-IR correlation spectroscopy

The properties of wood can be improved through steam-heat treatment. There are many studies about mechanical properties of steam-heat treated wood, but very few studies are on the aspects of chemical modifications. In this study, FT-IR spectra combined with SD-IR spectra, correlation coefficients and 2D-IR spectra are employed to analyze the chemical modifications of teak (Tectona grandis L.F.) wood during steam-heat treatment under treatment temperatures from 120 °C to 220 °C at intervals of 20 °C. Acetic acid, which is produced during steam-heat treatment, acts as a catalyst of condensation and degradation reactions of wood components. The changes of wood components are more and more intense with increasing the treatment temperature. The sensitivity of wood samples to thermal perturbation rises initially with increasing treatment temperature before falling back. The steam-heat treated wood under 180 °C is the most sensitive.

Graphical abstractThe chemical modifications of steam-heat treated wood under different temperatures were analyzed by FT-IR and SD-IR spectra, it showed the released acetic acid and other chemical reactions. The 2D-IR spectra revealed the different degree of sensitive of the wood samples to the thermal perturbation.Figure optionsDownload full-size imageDownload as PowerPoint slide