细胞壁微纤丝角和结晶区对木材物理力学性能影响研究进展

木材是由不同种类的细胞组成的天然材料,其实体物质是组成其结构的各类型细胞的细胞壁。细胞壁的超微构造主要包括微纤丝和结晶区,微纤丝角能表征纤维素微纤丝的取向,纤维素大分子链排列的有序程度及排列形态决定其结晶程度和微晶形态等结晶区特征。基于前人的研究,系统概述了细胞壁微纤丝和结晶区对木材物理力学性能影响的研究进展,重点围绕微纤丝角和结晶度2个方面,分别归纳了二者对木材密度、尺寸稳定性、木材声学等物理性质以及弹性模量、强度等力学性质的影响作用,同时阐述了微纤丝角与木材硬度和刚度以及结晶度与冲击韧性等的相互关系,并概述了细胞壁微晶形态对木材润湿性和纤维强度影响方面的研究进展,最后对今后的研究方向进行了展望。

Research progress on effect of microfibril angle and crystalline area in cell wall on wood physical and mechanical properties

Wood is one kind of natural materials consisting of various type of cells.Physical substance of wood is cell walls that form its structure.Ultrastructure of wood cell walls includes microfibril and crystalline area.Microfibril angle can characterize the orientation of cellulose microfibrils, while crystallinity and microcrystalline morphology are determined by the order and arrangement of cellulose macromolecular chains.Based on previous researches,this study systematically summarizes the effect of microfibril angle and crystalline area on basic material properties of woods.The effects of microfibril angle and crystallinity on physical and mechanical properties,such as dimensional stability and density,elastic modulus and strength are elaborated.The relationships between microfibril angle and hardness and stiffness as well as between crystallinity and impact toughness of wood are discussed,and the influence of microcrystalline morphology on wettability and fiber strength of woods is introduced.Finally,the perspectives for future study are also included.