有机物改性增强木材物理力学性能的研究进展

Research Progress on Improving Physical and Mechanical Properties of Wood by Organic Modification

我国人工林木材资源充足,在缓解优质木材资源短缺问题上发挥着重要作用。然而人工林木材密度低,力学性能差,还存在尺寸不稳定等问题。而有机物改性木材能够有效克服速生木材原生缺陷带来的问题,实现对木材物理力学性能的改善。相关方法主要利用木材的多级孔道结构将改性剂引入木材基体,使改性剂沉积于木材细胞壁或细胞腔中,并通过其自身及其与木材基体的物理化学作用,实现对木材多层物理结构及化学性质的调整。木材有机物改性方法有乙酰化改性、热固性树脂改性、反应型单体改性等。这些方法对木材多层级物理化学结构的具体作用机制不尽相同,且在尺寸稳定性、抗压强度、抗弯强度等方面的提升效果各异。因此,可以根据实际应用目的选择合适的改性方法,达到增强木材特定物理力学性能的目的。本文通过分析和总结国内外学者的研究成果,按细胞壁改性、细胞腔改性以及壁腔复合改性的分类方式对有机物改性提升木材物理力学性能的方式分类,系统总结分析三类改性方式下的木材物理力学性能以及对应处理方式下木材弱相结构变化,以期理清通过有机物改性方式对木材物理力学性能进行提升的共性实现机制,梳理现阶段通过有机物改性方式提升木材物理力学性能的优缺点以及未来发展方向,为人工林木材加工改良方法的发展提供科学系统的参考。

There is abundant plantation wood in China,which plays an important role in alleviating the shortage of high-quality timber resources.Howe-ver,the plantation wood has disadvantages of low density,low mechanical properties,poor dimensional stability and so on.The original defects of this material could be overcome through organic modification approaches.The improvement of physical and mechanical properties of wood could be realized.The performance of organic modification is mainly based on.The modification process is accomplished through the permeation of modifier into the wood matrix via the multi-stage pore structure of wood.The modifier is deposited in the wood cell wall or cell cavity.The adjustment of the multi-layer physical structure and chemical properties of wood is realized after the physical and chemical interaction of modifier with the wood components.The commonly used wood modification methods include acetylation modification,thermosetting resin modification,reactive monomer modification and so on.The specific action mechanism of these methods on wood multi-layer physical and chemical structure is different.The improvement results on dimensional stability,compressive strength,bending strength and other performance are also differentiated.Therefore,the modification method could be selected according to the application purpose to enhance the specific physical and mechanical properties of wood.By summarizing domestic and foreign researches in this area,this paper classifies the ways of organic modification to cell wall modification,cell cavity modification and cell wall-cavity modification.The research progress on the change of weak phase under the above three modification strategies and the physical and mechanical properties of the modified wood were summarized.The main purpose is untangling the common realization mechanism of improving wood physical and mechanical properties by organic modification.The strengths and weaknesses and development trend for improving wood performances by organic modification will also be analyzed.This review could provide a scientific and systematic reference to the development of processing improvement methods of plantation wood.