摘要
松脂渗出是含脂松木利用中的一个严重问题,探究过热蒸汽处理对松脂的松节油含量和软化点的影响可为含脂木材过热蒸汽干燥工艺制定提供理论依据。采用两阶段过热蒸汽处理工艺对松脂进行热处理,通过热重分析仪(TGA)、热机械分析仪(TMA)、色度计和高效液相色谱-质谱(HPLC-MS)等测试技术,分析了过热蒸汽处理对松脂的残余松节油含量、软化点、颜色和化学成分变化的影响,并检测和评估了过热蒸汽处理木材的抗松脂渗出效果。结果表明,在过热蒸汽处理阶段Ⅰ,随着处理时间的增加,松节油含量降低,并且去除效率也降低,这是由松节油含量降低后松脂变得黏稠所致。在过热蒸汽处理阶段Ⅱ,随着温度的升高和处理时间的增加,残余松节油含量降低,松脂软化点提高。残余松节油含量与松脂软化点高度相关,松节油含量越低,松脂软化点则越高,其中160℃处理9 h的松脂样品软化点可达60℃以上。但松脂的软化点不仅受残余松节油含量影响,也受到高温的改性作用,因为过热蒸汽处理可使松脂颜色加深,并导致松脂发生脱氢、异构化和氧化反应。木材的抗松脂渗出试验表明,过热蒸汽处理可有效避免含脂木材松脂渗出,因此可将松脂的过热蒸汽处理工艺调整后应用于松木锯材干燥,避免木制品在使用过程中发生松脂渗出。
Resin in pine wood possesses fluidity,particularly evident as temperatures rise,leading to resin softening and an augmented fluidity.This leads to resin exudation during the use of pine products,resulting in both unsightly appearance and diminished performance.Therefore,the removal and fixation of resin are necessary for resinous wood.The purpose of this study is to investigate the effect of superheated steam treatment on the turpentine content and softening point of resin,so as to provide a theoretical basis for the drying schedule of resinous wood.Hence,the resin is heat-treated using a two-stage superheated steam process.Using the thermogravimetric analyzer(TGA),thermomechanical analyzer(TMA),colorimeter,and liquid chromatography-mass spectrometry(HPLC-MS) techniques,the effects of superheated steam treatment on the residual turpentine content,softening point,color,and chemical composition of resin were analyzed,and the anti-resin exudation effect of the superheated steam treated wood was also tested and evaluated.The results showed that,in the superheated steam treatment stage Ⅰ,with the increase of treatment time,the turpentine content decreased,and the removal efficiency also decreased,because the resin became sticker after the turpentine content decreased.In superheated steam treatment stage Ⅱ,with the increase of temperature and treatment time,the residual turpentine content decreased and the softening point of pine resin increased.The residual turpentine content was highly correlated with the softening point of the resin.The lower the turpentine content,the higher the softening point of the resin.The resin sample treated at 160 ℃ for 9 h exhibits a softening point exceeding 60 ℃.However,the softening point of resin is not only affected by the content of residual turpentine,but also by the modification of high temperature,because the superheated steam treatment can deepen the color of resin and lead to dehydrogenation,isomerization,and oxidation of resin.The anti-resin exudation test of wood shows
作者
曹惠敏
黄赛赛
周永东
伊松林
殷方宇
高鑫
周凡
CAO Huimin;HUANG Saisai;ZHOU Yongdong;YI Songlin;YIN Fangyu;GAO Xin;ZHOU Fan(Research Institute of Wood Industry,Chinese Academy of Forestry,Beijing 100091,China;College of Materials Science and Technology,Beijing Forestry University,Beijing 100083,China)
出处
《林业工程学报》
CSCD
北大核心
2024年第1期85-91,共7页
Journal of Forestry Engineering
基金
中央级公益性科研院所基本科研业务费专项资金(CAFYBB2021QA003)。
关键词
松脂
松节油
溢脂
软化点
过热蒸汽
木材干燥
resin
turpentine
resin exudation
softening point
superheated steam
wood drying
