Thermal treatment is an effective method for improving the dimensional stability of wood; however, it typically requires high temperatures. To achieve low-temperature heat treatment, this study employed wood samples impregnated with 10 % tannin acid (TA) and examined their changes in dimensional stability and chemical components after heat treatment at various initial moisture content levels. The results revealed that the TA-10 %-HT group exhibited enhanced dimensional stability. Specifically, both the tangential and radial moisture swelling decreased by 21.7 % and 11.8 %, respectively. FTIR and XRD analysis indicated that the presence of tannin acid catalytically facilitated the degradation of hemicellulose. Moreover, an increase in moisture content resulted in the ionization of TA, amplifying acidity and further affecting cellulose degradation. TGA demonstrated that TA impacted the thermal stability of heat-treated materials by lowering the initial decomposition temperature of wood components and increasing the residual weight of wood. Overall, pretreatment with TA impregnation and moisture content significantly improved the dimensional stability of Chinese fir wood and altered its chemical composition. This approach holds considerable potential for enhancing wood properties through a low-energy consumption method during the heat treatment process, expanding the practical application of wood.

中文翻译：

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单宁酸浸渍预处理对热处理杉木尺寸稳定性和化学成分的影响

热处理是提高木材尺寸稳定性的有效方法；然而，它通常需要高温。为了实现低温热处理，本研究采用了浸渍 10% 单宁酸 (TA) 的木材样品，并检查了在不同初始含水量水平下热处理后尺寸稳定性和化学成分的变化。结果表明，TA-10%-HT 基团表现出增强的尺寸稳定性。具体来说，切向和径向湿膨胀分别降低了 21.7% 和 11.8%。FTIR 和 XRD 分析表明单宁酸的存在催化促进了半纤维素的降解。此外，水分含量的增加导致TA电离，增强酸度并进一步影响纤维素降解。TGA 证明，TA 通过降低木材成分的初始分解温度和增加木材的残余重量来影响热处理材料的热稳定性。总体而言，TA浸渍和含水量预处理显着提高了杉木的尺寸稳定性并改变了其化学成分。这种方法在热处理过程中通过低能耗方法增强木材性能，扩大木材的实际应用具有巨大的潜力。