WOOD RESEARCH Volume 62, Number 5, 2017
Zhe Wang, Bailing Sun, and Junliang Liu

Investigation of volatile products released during vacuum heat treatment of larch wood

The aim of this study was to investigate the components of volatile by-products released at different treatment temperatures. For this objective, the aldehydes and ketone were trapped in DNPH solution and the aldehyde and ketone derivatives were analyzed by HPLC. The acids and alcohols were trapped in deionized water and analyzed by HPLC and GC. The other volatile organic compounds were trapped on Tenax TA tubes and analyzed by GC-MS. The results showed that there was an increasing trend in the concentrations of aldehydes, acids, and alcohols with the increasing treatment temperature. The heat treatment at higher temperature resulted in more kinds of volatile organic compounds.

WOOD RESEARCH Volume 64, Number 1, 2019
Bailing Sun, Zhe Wang, and Junliang Liu

Study on color and surface chemical properties of Eucalyptus pellita wood subjected to thermo-vacuum treatment

The objective of this study was to investigate the color and surface chemical properties of Eucalyptus pellita wood subjected to thermo-vacuum treatment. Specimens were thermally modified in a vacuum at various temperatures for 4 h. The color parameters of untreated and heattreated samples were measured using the CIE Lab method. Surface chemical properties were evaluated by UV-Vis spectroscopy, 13C NMR spectroscopy and X-ray photoelectron spectroscopy. The results showed that eucalypt wood became darker uniformly throughout with the increase of treatment temperature, and the total color variation ΔE* obviously increased at higher temperature. The spectral changes indicated that degradation and oxidation of hemicellulose, lignin and extractives contributed to the formation of color substances during thermo-vacuum treatment. Crystalline content of carbohydrates increased. The decrease in O/C ratio signified the increase of the relative content of lignin and extractives on the wood surfaces in the heating process.