摘要
速生木材及其制品易受环境温湿度的影响而产生尺寸变形、霉变、腐朽等缺陷,极大地限制了其在户外领域的应用。糠醇改性是一种环境友好型木材改性技术,可以提高改性木材的尺寸稳定性、防霉防腐性以及硬度等性能,进而赋予改性木材更高的使用价值和更广的应用前景。尽管学者们对糠醇改性木材做了大量基础理论和应用研究,但对糠醇改性木材的反应机理以及糠醇原位聚合和糠醇交联木材细胞壁主要成分这两个竞争反应的影响因素尚未达成共识。笔者围绕糠醇改性反应机理,从糠醇改性体系本身(包括催化剂、糠醇浓度、稀释剂、分子量等),糠醇与木材细胞壁主要成分的反应倾向性,以及细胞壁主要成分可控脱除这3个方面进行了概述总结;列举了现阶段能够证明糠醇发生化学反应的现代仪器分析方法,并从化学反应分子热力学角度进一步阐明了糠醇原位聚合和糠醇交联木材细胞壁这两个竞争反应的机制以及发生的概率;最后重点探讨了基于细胞壁可控脱除体系使得纤维素、半纤维素以及木质素与糠醇分别发生交联反应的可能性及方法,以期为探索实木改性机制提供新的思路。
Fast-growing wood and bamboo have been widely used in the fabrication of wood products and paper due to their short growth cycle,excellent processability and renewability.Nevertheless,the moisture content of fast-growing wood and bamboo products are susceptible to change depending on the environmental temperature and humidity,consequently causing dimension instability and decay by mold and fungi.These drawbacks infinitely limited their outdoor applications.As an environmentally friendly modification technology,furfurylation can improve the dimension stability,decay and mold resistance,and hardness of wood and bamboo products,endowing potential higher use values and broader applications.Research on the fundamental theory and practical applications of furfurylation has been conducted elaborately by many researchers around the world.However,there is no universal agreement on the mechanisms of furfuryl alcohol self-polymerization and grafting reaction with principal wood cell wall components,neither any confederal agreement on the reaction preference between the self-polymerization and grafting reaction of furfuryl alcohol.In this review,the furfuryl alcohol modifying system(including the use of catalysts,the concentration of furfuryl alcohol,solvents,and molecular weight of the oligomer of furfuryl alcohol,etc.),and the propensity of the reaction between furfuryl alcohol and cellulose,hemicellulose and lignin,as well as the controlled removal of hemicellulose and lignin were systematically summarized based on the reaction mechanism of furfurylation.Various advanced analysis technologies that could attest and identify all possible reactions between furfuryl alcohol and wood cell wall components were also demonstrated in this paper,such as the Confocal Laser Scanning Microscopy,Nuclear Magnetic Resonance,Fourier Transform infrared spectroscopy and Gel Permeation Chromatography,etc.Moreover,the mechanisms of furfuryl alcohol self-polymerization and grafting reactions were further elucidated from the perspective of mole
作者
冷魏祺
何盛
张雪峰
翟胜丞
王新洲
潘彪
石江涛
LENG Weiqi;HE Sheng;ZHANG Xuefeng;ZHAI Shengcheng;WANG Xinzhou;PAN Biao;SHI Jiangtao(College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037,China;College of Light Industry and Food Engineering,Nanjing Forestry University,Nanjing 210037,China;China National Bamboo Research Center,Hangzhou 310012,China;Department of Sustainable Bioproducts,Mississippi State University,Mississippi State,Starkville MS 39762,USA)
出处
《林业工程学报》
CSCD
北大核心
2021年第6期35-43,共9页
Journal of Forestry Engineering
基金
国家自然科学基金(32001259)
江苏省自然科学基金(BK20200796)。
关键词
木材改性
糠醇改性
原位聚合
细胞壁
化学交联
可控脱除
wood modification
furfurylation
self-polymerization
cell wall
chemical bonding
controlled removal
