真空热处理对落叶松木材表面性能的影响1）

摘要

We studied the Larix kaempferi wood specimens by vacuum heat treatment at 160℃, 180℃, 200℃, 220℃, and 240℃for 4 h.We measured the contact angles using different test liquid , calculated surface free energy , and analyzed the chemical changes of wood by FTIR and XPS .The contact angles of different liquid on the surface of the heat treated sam-ples were higher than those of the untreated samples .The surface free energy decreased with the increase of heat treatment temperature.By FTIR, the number of hydroxyl and carbonyl groups decreased and lignin composition degraded with the in -crease of temperature.By XPS spectra, the heat treatment decreased the O/C atomic ratio of the wood surface , increased C1, decreased C2, and was with no obvious change rule in C 3.%以落叶松木材为研究对象，分别在160、180、200、220、240℃的条件下对其进行真空热处理4 h。测试了不同极性的液体在木材表面的接触角，并计算了木材的表面自由能；利用傅里叶变换红外光谱和X射线光电子能谱分析了木材在热处理过程中官能团和表面化学成分的变化。结果表明：经真空热处理后，木材的润湿性下降；极性不同的液体在落叶松热处理材表面的接触角大于在未处理木材表面的接触角。随着热处理温度的升高，木材的表面自由能呈下降趋势。红外谱图显示，随着热处理温度的升高，木材中羟基吸收峰与羰基吸收峰的强度均呈下降趋势，部分木质素成分发生降解。 XPS测试结果显示，热处理后落叶松表面C元素相对值增加，氧碳比下降，从C原子结合形式来看，C1相对值增加，C2呈减少的趋势，C3无明显变化规律。