摘要
为探究溶液体系对烷氧基硅烷处理后杨木尺寸稳定性的影响,采用5,10和15 g的丙基三甲氧基硅烷(PTMS)分别与15,10和5 g的甲基三甲氧基硅烷(MTMS)复配,然后通过气相辅助迁移法处理杨木,考察了密度、质量增加率、接触角和尺寸变化率的变化。结果表明:PTMS质量分数为50%时,处理后木材常温下浸水7 d后的吸水率为27.3%,尺寸变化最小,水接触角为(125.3±1.3)°。此外,试验数据还显示出溶液体系中PTMS质量分数越高、MTMS质量分数越低,改性木材的质量增加率和密度增长越少,疏水性越好的趋势。溶液体系中的PTMS质量分数与改性木材疏水性呈正相关,而PTMS质量分数过高或过低都会导致尺寸稳定性降低。可能的原因是MTMS与PTMS对木材性质改善的机理不同,小分子的MTMS质量分数越高,越易渗透进木材细胞壁,从而形成交联网络支撑细胞壁结构,有利于提高改性木材的耐腐朽、尺寸稳定性等性质;而PTMS及其改性的烷氧基硅烷所形成的低表面能交联网络穿透细胞壁阻力较大,部分存在于细胞壁外,对水分交换影响更大。研究表明,PTMS/MTMS气相辅助迁移法改性木材的性质与溶液体系有关。
As well known,methyltrimethoxysilane(MTMS) is effective to improve decay resistance and dimensional instability.However,its treatment process and suitable dosage have not been studied thoroughly.The aim of this experiment was aimed at exploring the effect of solvent systems on the dimensional stability of poplar after treatment with alkoxysilanes.Using 5,10 and 15 g propyltrimethoxysilane(PTMS) compounded with 15,10 and 5 g MTMS,respectively,poplar samples were treated by the gas-assisted migration method,and the changes of density,mass increase rate,contact angle and dimensional change were investigated.The results showed that,with 50% PTMS,the water absorption of the treated wood was 27.3% after 7 d of immersion in water at room temperature.The water contact angle of the treated wood was(125.3±1.3)°.Moreover,the higher the mass ratio of PTMS and the lower the mass ratio of MTMS in the solution system,the smaller the mass increase rate and density growth,and the better the hydrophobicity.The PTMS mass ratio was positively correlated with the increase in hydrophobicity of the treated wood,while the dimensional stability was reduced when the PTMS mass ratio was too high or too low.The possible reason was that MTMS and PTMS had different mechanisms to improve wood properties,of which the higher the mass fraction of small molecules of MTMS,the easier it was to penetrate wood cell walls,thus forming a crosslinked network to support the cell wall structure,which was conducive to the improvement of the modified wood properties such as decay resistance and dimensional stability.PTMS and its modified alkoxysilane formed by the low surface energy of the crosslinked network to penetrate through the cell wall resistance,partially existed outside the cell walls,which had a greater impact on water exchange.The low surface energy crosslinked network formed by PTMS and its modified alkoxysilanes had a higher resistance to penetrate cell walls,and part of it existed outside the cell walls,which had a greater effect on water ex
作者
刘雨晗
石江涛
冷魏祺
黄琼涛
刘海良
LIU Yuhan;SHI Jiangtao;LENG Weiqi;HUANG Qiongtao;LIU Hailiang(College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037,China;Yihua Life Technology Co.Ltd.,Shantou 515834,China;Jiangsu Senmao Bamboo and Wood Industry Co.Ltd.,Yixing 214231,China)
出处
《林业工程学报》
CSCD
北大核心
2024年第1期61-66,共6页
Journal of Forestry Engineering
基金
国家重点研发计划(2017YFD0600204)
江苏高校“青蓝工程”资助项目(2022年)。
