文献类型：期刊文献

英文题名：The Viscoelastic and Hygroscopicity Behavior of Delignified and Densified Poplar Wood

作者：Wang, Jiajun[1] Chai, Yubo[2] Liu, Junliang[2] Zhu, J. Y.[3]

第一作者：Wang, Jiajun

通信作者：Chai, YB[1];Zhu, JY[2]

机构：[1]Natl Ctr Archaeol, Beijing 100013, Peoples R China;[2]Chinese Acad Forestry, Res Inst Wood Ind, Beijing 100091, Peoples R China;[3]USDA Forest Prod Lab, Madison, WI 53726 USA

年份：2023

卷号：14

期号：9

外文期刊名：FORESTS

收录：;EI(收录号：20234014822127);Scopus(收录号：2-s2.0-85172728415);WOS:【SCI-EXPANDED(收录号:WOS:001071766700001)】；

基金：Support was also received from Chinese Academy of Forestry for advanced imaging analysis.

语种：英文

外文关键词：delignification; densification; viscoelasticity; hygroscopicity; FTIR imaging microscopy

摘要：The combination of alkaline delignification and densification was applied to improve wood mechanical strength. Poplar wood samples were subjected to alkali delignification with varying degrees of lignin and hemicellulose removal followed by hot pressing. Dynamic mechanical performances and dynamic sorption behavior of the untreated and densified wood were then evaluated. Results showed that appropriate removal of lignin can improve the stiffness of densified wood and reduce moisture sorption and the numbers of sorption sites. Fourier transform infrared (FTIR) microscopy along with X-ray diffraction (XRD) were used to explain the viscoelastic and hygroscopicity of delignified and densified wood. Hemicelluloses and lignin were selectively dissolved during alkali treatment. Wood crystallinity was increased after alkali treatment at a moderate concentration of 2%, beneficial to improving the dimensional stability and mechanical performance of delignified and densified wood. The crosslinking of cellulose chains through hydrogen bonding, the decreased content of free hydroxyl groups, and the increased crystallinity in the cell wall contributed to higher storage modulus and lower hydrophilicity. The results support mild delignification and densification as a feasible way towards extending the service life of wood products used as structural materials.