木质复合材料胶合界面的微观力学性能表征及破坏机理研究

Wood gluing materials can greatly improve the utilization of wood, its performance depend on woods and adhesives, and are more dependent on the wood/adhesive interface. At present, microscopic technology and X ray imaging technology were used to study the permeability of adhesives in bonding interface, however, the mechanical properties of interfaces cannot be measured until now, which greatly limits the development of wood gluing materials. This project is going to prepare specific samples by FIB and spin coating methods, and use uniaxial micro-column compression and nano-scratch test modes to directly characterize the micro bonding properties and fracture mechanisms. The objective is to develop novel and practical methods to characterize wood/adhesive interface, and to understand the effects of wood types, adhesive types, wood process and bondline formation on the adhesion, and to establish the relationships among wood and adhesive structure, curing process, wood/adhesive interface micro-mechanical properties and wood gluing material performance. It will be first time to directly measure the interface fracture and micro mechanical properties, which has important scientific value for further improving wood bonding mechanism, and has important guiding significance for effective utilization of wood and upgrading of product properties.

木质胶合材料的性能取决于木质材料和胶粘剂，更取决于起载荷传递作用的界面。目前，研究者只能通过显微技术和X射线成像技术判断胶合界面中胶粘剂的渗透性能，但无法测定重要的界面力学性能指标，这极大限制了木质胶合材料的发展。本项目拟采用聚焦离子束刻蚀技术（FIB）和旋涂制样，通过单轴微柱压缩和纳米刮痕测试模式，研发用于表征木质胶合材料界面微观胶合和极限力学行为的实用测试手段，在此基础上考察木材种类、预处理方式、胶粘剂种类与固化工艺等因素对界面微观力学性能及胶合材料宏观力学性能的影响，结合FTIR、显微技术等结构表征手段，建立木材与胶粘剂结构-固化工艺条件-胶合界面微观力学性能-胶合材料宏观力学性能的关联机制。本项目将首次直接测量木材细胞壁与胶层界面破坏和微观力学性能，对进一步完善木材胶合机理具有重要的科学价值，对木材的有效利用、产品性能升级具有重要指导意义。

木质胶合材料的性能取决于木质材料和胶粘剂，更取决于起载荷传递作用的界面。本项目采用聚焦离子束刻蚀技术（FIB）制备木材细胞壁-胶层界面微柱样品，通过单轴微柱压缩实验和有限元分析，研究了界面微观力学性能与胶合材料宏观力学性能的构效关系，建立木质胶合材料微观界面强度预测模型。在此基础上，从微观力学角度探究了紫外辐照和冻融老化对木质工程材料胶合界面力学性能的影响，并通过纳米压痕的Mapping技术实现了木质胶合界面力学性能大范围、高精度可视化表征，该技术可用于表征早材细胞壁及其胶合界面的微观力学性能。本项目首次直接测量木材细胞壁与胶层界面破坏和微观力学性能，对进一步完善木材胶合机理具有重要的科学价值，对木材的有效利用、产品性能升级具有指导意义。