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.