热处理升温速率对柞木微观结构和物理力学性能的影响  

Effect of heating rate on microstructure and selected physical and mechanical properties of heat-treated Mongolian oak wood

作　　者：陆健 丁涛 施静波 杜静静 LU Jian;DING Tao;SHI Jingbo;DU Jingjing(College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]南京林业大学材料科学与工程学院,南京210037

出　　处：《林业工程学报》2023年第6期76-83,共8页Journal of Forestry Engineering

基　　金：江苏省基础研究计划(BK20200790)。

摘　　要：升温速率对木材热处理的产品性能和反应机制都会产生显著影响,对生产实践操作也具有重要作用,但相关研究十分缺乏。以柞木为试样,在常压过热蒸汽条件下以5,10,15,20和25℃/h的升温速率分别升温至200℃进行热处理。分析处理材的主要化学组分和结构,并测试其主要物理力学性能,探索升温速率对处理材结构和性能的影响,为木材热处理技术的优化应用提供参考。结果表明:热处理升温速率对柞木化学组成和结构都具有显著影响。细胞壁半纤维素含量随升温速率的减小而下降,而木素的相对含量则随着升温速率的减小而提高,纤维素含量受热处理影响很小,但微纤丝结构发生明显变化。不同升温速率水平下热处理柞木的主要性能也呈规律性变化。热处理后柞木的静态与动态弹性模量均有所增加,且都随着升温速率的下降先增大后减小,与微纤丝结晶度的变化趋势高度一致。热处理后柞木的吸湿性随升温速率的减小而逐步下降,并与半纤维素浓度的变化密切相关。综上可见,升温速率是调节热处理柞木性能的有效工艺参数,但试材性能的变化与升温速率之间并非都是线性关系,应根据木材热处理的主要性能需求,结合生产效率和安全性等综合因素确定木材热处理的升温速率。The heating rate has a significant effect on both product properties and reaction mechanisms of the wood heat treatment,which plays an important role in production practices.However,there is a lack of relevant study.In this study,Mongolian oak wood was heat-treated with a heating rate of 5,10,15,20 or 25℃/h respectively under atmospheric pressure superheated steam conditions to 200℃.This study was aimed at contributing to this growing area of research by analyzing the main chemical components and structures of the treated wood and examining the main physical and mechanical properties,in order to explore the effect of the heating rate on the structure and properties of the treated wood and to address the problem of reference for the optimization of the wood heat treatment technology.This research work had brought about a discovery that the heating rate of heat treatment had a significant effect on the chemical composition and structure of the Mongolian oak wood.The hemicellulose content of the cell wall decreased with a decrease of heating rate,while the relative content of lignin increased with the decrease of heating rate.Additionally,the cellulose content was slightly affected by the heat treatment,but the structure of microfibril changed significantly.It was also proved that the main properties of the heat-treated Mongolian oak wood showed regular changes at different levels of heating rates.Besides,the static and dynamic modulus of elasticity of the Mongolian oak wood increased after the heat treatment,and both followed an up-and-down pattern with the decrease of the heating rate,which was highly consistent with the trend of microfiber crystallinity.The hygroscopicity of the Mongolian oak wood after the heat treatment decreased gradually with the decrease of the heating rate,which was closely related to the change of hemicellulose concentration.The findings of this research have led to the conclusion that the heating rate is an effective process parameter to regulate the performance of the heat-treated Mo

关 键 词：热处理 升温速率 柞木 微观结构 物理力学性能 

分 类 号：S781.7[农业科学—木材科学与技术]