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首页> 外文期刊>Journal of Materials Science >Analysis of stress relaxation on the basis of isolated relaxation spectrum for wet wood
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Analysis of stress relaxation on the basis of isolated relaxation spectrum for wet wood

机译：基于孤立松弛谱的湿木应力松弛分析

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In this study, we investigated the relaxation properties of wet wood based on spectra isolated from the whole wood relaxation spectrum, calculated using Alfrey's approximation at temperatures ranging from 25 to 85 °C. Three relaxation processes were identified, I, II, and III, in the order of low to high temperature, and these were attributed to local molecular motions of hemicellulose, lignin, and cellulose, respectively. Processes I and II (but not III) depended on temperature and the apparent activation energy, which was calculated from the temperature dependence of their relaxation time and was approximately 85 kJ/mol (20 kcal/mol) for both processes. The peak positions and intensity of the isolated relaxation spectra indicated that the molecular motion of the relaxation processes in the temperature range studied represent not whole molecular motion, but rather local molecular motion of the hemicellulose and lignin matrix. This study also demonstrated that the isolation procedure using a Gaussian function can be used to analyze the relaxation process of wood.
机译：在这项研究中，我们基于从整个木材弛豫谱中分离出的光谱，研究了湿木材的弛豫特性，该光谱是使用Alfrey近似在25至85°C的温度范围内计算得出的。确定了三个松弛过程，分别是从低温到高温的顺序I，II和III，这分别归因于半纤维素，木质素和纤维素的局部分子运动。方法I和II（但不是III）取决于温度和表观活化能，这是由它们的弛豫时间的温度依赖性计算得出的，两种方法均约为85 kJ / mol（20 kcal / mol）。分离的弛豫谱的峰位置和强度表明，弛豫过程在所研究的温度范围内的分子运动并不代表整个分子运动，而是代表了半纤维素和木质素基质的局部分子运动。这项研究还表明，使用高斯函数的隔离过程可用于分析木材的松弛过程。

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