化学处理木材的动态粘弹性研究

为了弄清楚不同化学试剂处理引起木材内部分子构造的变化及其分子的运动状态，该研究针对杉木试材，采用动态粘弹性分析仪，测定了含水率在纤维饱和点状态下脱木素处理木材、DMSO处理木材和非晶化处理木材以及素材，在-100～10℃、0.5～10 Hz的动态粘弹性.研究结果表明:①在-100～10℃范围内观察到两个松弛过程，-30℃附近的α松弛过程和-100℃附近的β松弛过程；②频率越高，损耗模量峰值对应的温度越高,贮存模量随着温度的升高而降低；③α松弛过程中非晶化处理木材的活化能最高，DMSO处理木材次之,脱木素处理木材与素材接近；④木材发生α松弛过程的主要原因是吸着水分子的回转取向运动，发生β松弛过程的主要原因是无定形区细胞壁物质中的伯醇羟基基团的运动. 

Viscoelastic properties of wood treated by different reagents

To investigate the structure change and movement status of molecule in wood caused by different reagents, the dynamic viscoelastic properties of Chinese fir wood treated by NaClO3, DMSO, DEA-SO2-DMSO and non-treated wood under the fiber saturated point, temperature from –100-10℃ at frequencies between 0.5 and 10 Hz were examined by DMA. We draw the following conclusions:①It is observed that there are two stress relaxation processes in the temperature range of –100-10℃,α-relaxation process at around -30℃ and β-relaxation process at around -100℃.②The higher the frequency value is, the higher loss modulus E″peak temperature value is. The value of storage modulus E′decreases as the temperature rises.③In α-relaxation process, the value of activation energy of DEA-SO2-DMSO-treated wood specimens is the highest, DMSO-treated wood specimens is the second, the value of activation energy of NaClO3-treated wood specimens and that of non-treated wood specimens are the lowest, and the two values are very close.④The rotational motion of the adsorbed water molecules is the main reason that lead to the α-relaxation process of wood. The β-relaxation process is due to the motions of the methylol groups of the cell-wall polymers in the non-crystalline region.