基于POSS核壳结构构建的竹集成材胶合界面增强增韧及作用机制研究

竹集成材强度高、幅面大、结构均一，作为工程结构材在户外建筑中极具应用前景。但由于其胶层脆性大、胶接强度不足，胶合界面极易产生应力集中造成开裂，严重影响了其使用寿命和品质，是长期制约其在户外建筑领域推广应用的共性科学问题。本项目拟以笼型聚倍半硅氧烷（POSS）为核，采用超支化聚合物接枝修饰表面，构筑刚柔并济POSS-超支化聚合物核壳结构，增韧竹集成材用酚醛树脂胶黏剂，增强界面结合强度，减少/消除胶接界面应力集中；重点考察POSS核壳结构及用量对酚醛树脂性能以及固化后结构形貌、断裂破坏形式、裂纹演化路径等的影响规律，解析POSS核壳结构改性酚醛树脂与竹材界面胶接形态、胶接强度、界面受力破坏形态等间的构效关系，阐明应力传递及能量耗损机制，揭示竹材-树脂胶合界面增强增韧机理，以期解决竹集成材开裂的技术瓶颈问题，为竹集成材产品升级提供科学依据和技术支撑，进而推动竹产业健康、快速、可持续发展。

Glue-laminated bamboo has great application prospect in outdoor buildings as an engineering structural material because of its high strength, large size, and uniform structure. However, due to the brittleness of the adhesive layer and the insufficient bonding strength, the bonding interface is prone to stress concentration and cracking, which seriously affects its service life and quality. The cracking of glue-laminated bamboo becomes a common scientific problem that restricts its promotion and application in the field of outdoor construction for a long time. This project aims to build a reactive POSS-hyperbranched polymer core-shell structure with both rigidity and flexibility by grafting the hyperbranched polymer to the core POSS surface, to toughen the phenol formaldehyde resin, strengthen the interfacial bonding strength, and to eliminate the interfacial stress concentration between bamboo and resin. The influence law of the structure and amount of POSS core-shell structure on the properties of phenol formaldehyde resin adhesives, the structure and morphology, fracture failure forms, and crack evolution path of the cured phenol formaldehyde resin will be mainly investigated. And the structure-activity relationship between POSS core-shell modified phenol formaldehyde resin and the interfacial bonding morphology, bonding strength, and interfacial stress failure morphology of resin-bamboo interface will be also clarified, thus illuminating the stress transfer and energy dissipation mechanism, and revealing the reinforcing and toughening mechanism of bonding interface between bamboo and phenol formaldehyde resin. This project is expected to solve the technical bottleneck of glue-laminated bamboo cracking and to provide scientific basis and technical support for the upgrading of glue-laminated bamboo products, thus promoting the healthy, rapid and sustainable development of bamboo industry.application.