热改性木材化学成分及构造变化与耐腐性响应机制研究

热改性处理是提高木材耐腐性的环保型技术手段，但是处理材耐腐性受树种﹑热改性工艺﹑应用环境等的影响显著。针对热改性木材耐腐机理尚不明确的现状，本项目选择了几种典型的热改性木材树种，分别以木材﹑脱木质素木材以及分离得到的木材组分为研究对象，考察不同工艺的热改性对木材主成分及抽提成分的影响规律，重点研究在木材腐朽过程中起到降解屏障作用的木质素的组成及分布的变化规律，以及热改性工艺对“假木质素”的形成和分布等的影响；在此基础上，研究热改性造成的木材化学成分和构造变化对不同腐朽菌的产酶活力﹑产酶种类﹑酶扩散﹑自由基形成等的影响规律，重点研究木质素对纤维素酶的吸附特性；结合不同工艺热改性木材的耐腐性以及腐朽过程中木材化学成分及构造的变化，深入探讨“热改性工艺—木材化学成分及构造—真菌降解模式—木材耐腐性”之间的复杂响应机制，总结热改性木材的耐腐机理，为热改性木材耐腐性提升提供理论基础及技术手段。

Thermal modification is an environmentally-benigh technology to improve the decay resistance of wood, however, the decay resistance of modified wood is significantly influenced by wood species, thermal modification process, and the application environment. Viewing the current situation of obscure mechanism on decay resistance of thermally-modified wood, we select several typical wood species used for thermal modification in this project, and investigate the influence of various processes of thermal modification on the primary components as well as the extractives of wood by using wood, delignified wood, and wood constituents separated from wood as the subjects of research. The focuses of this part is the change on structure and distribution of lignin, which serves as degradation barrier in wood decay, and also the influence of thermal modification process on the formation and distribution of “Pseudolignin”; based on these, the influences of the chemical and structural changes of wood caused by thermal modification on the activity, species, and distribution of fungal enzymes, and also the formation of free radicals are investigated, with an emphasis on the adsorption of cellulases by lignin; together the decay resistance of various thermally-modified wood,the chemical and structural changes of wood during decay process, the complicated response mechanism between “thermal modification process-chemical and structural changes of wood-fungal degradation mode-decay resistance of wood”can be intensively discussed,and the decay resistance mechanism of thermally-modified wood can be summarized. It can provide theoretical foundation and technology for the improvement on decay resistance of thermally-modified wood.