热固性聚氨酯应用广泛且需求量大，但稳定的交联结构让其不能回收再成型，造成资源浪费和环境污染。受酚羟基与异氰酸酯的可逆反应的启发，本研究利用天然多元酚没食子酸和漆酚替代多元醇，与多异氰酸酯进行可逆交联，实现聚氨酯中共价键的重组和材料的自修复与可回收。通过酯化、醚化、Mannich反应和物理共混的方式，液化没食子酸和调节酚羟基活性；用固体核磁表征交联网络中共价键的变化，并用热分析和流变方法研究可逆反应动力学和可逆交联的流变特性，获得再成型工艺条件；用显微手段评价疤痕的自修复程度，用静态热分析和溶胀性测试再生材料的热固性恢复程度。最后通过热、力学性能的测试，探讨没食子酸/漆酚配比、再生条件对聚氨酯性能的影响。本研究提出了一个聚氨酯可逆交联的新体系，是一种具有普遍意义的新方法。与现有研究相比，本体系具有更显著的应用前景，同时也有利于推动林特资源没食子酸和漆酚的高附加值利用。

Thermosetting polyurethane is widely used and its demand is very huge, but its stable crosslinking network makes it implastic and unrecoverable, which lead to resource waste and environment pollution. Inspired by the reversible reaction between phenol hydroxyl and isocyanate, this project is plan to prepare the self-healing and recyclable thermosetting polyurethane with covalent adaptable networks via replacing polyols by natural polyphenols gallic acid and urushiol to crosslink reversibly with polyisocyanates. Esterification, etherification, Mannich reaction and physical blending are applied in order to liquefy gallic acid derivatives and adjust the reactivity of the phenols. Solid nuclear magnetic resonance will be used to characterize the changes of the covalent bonds in the networks. thermoanalysis and rheology could be utilized to study the kinetics of the reversible reaction and the rheology properties of the thermosetting polyurethane, so that the remolding process conditions could be available. The microstructure of self-healing scar could be observed by the microscopic method, and the thermosetting properties of the remolding materials can be confirmed by static thermal analysis and swelling method. Finally we will test the thermal and mechanical properties of the materials before and after self-healing or recycled to discuss the effect of gallic acid/urushiol ratios and remolding process on the properties of recycled materials. This proposal present a new system that the thermosetting polyurethane networks can crosslink reversibly, it is a universal new technology. Compared with the existing research, its application prospect is more remarkable, meanwhile, it will promote the higher-value utilization of these forestry resources gallic acid and urushiol.