生物基反应型阻燃剂具有廉价易得、低毒、可再生和生物降解等优点，因此是实现聚氨酯弹性体阻燃性的理想选择。一方面目前生物基反应型阻燃剂存在品种单一，需要多步化学修饰过程，所得聚氨酯弹性体力学和阻燃性能不能兼顾等问题；另一方面林产生物质单宁酸特有的多酚结构使其具有天然的阻燃增强和可逆交联的能力。基于环保和仿生理念，本项目拟选择单宁酸直接作为反应型阻燃剂和交联剂，与桐油基异氰酸酯预聚体反应制备生物基可逆交联阻燃聚氨酯弹性体。通过改变固化工艺调控所得聚氨酯弹性体的结构组成，并阐明其与阻燃性能及力学性能之间的关系，建立阻燃和力学性能之间的关联性，最终确定较优的固化工艺使材料兼具良好的阻燃和力学性能。同时利用氨基甲酸芳酯键的可逆性实现聚氨酯弹性体的可回收性。本项目的研究将开发一种具有潜在应用价值的制备高性能生物基阻燃聚氨酯弹性体的新方法，同时将为推动传统林产资源的高值化利用提供新的研究思路。

Bio-based reactive flame retardants can not only improve the flame retardancy of polyurethane elastomers, but also have the advantages of wide sources, low toxicity, renewable and biodegradable properties. On the one hand, the current bio-based reactive flame retardants have some deficiencies, such as less variety, multiple chemical modification processes, and the excellent mechanical and flame retardancy of resulting polyurethane elastomers can’t be achieved at the same time. On the other hand, the unique polyphenol structure of tannic acid makes it has natural flame retardant enhancement and reversible cross-linking ability. Based on the concept of environmental protection and bionics, this project intends to apply tannic acid as a reactive flame retardant and cross-linking agent to react with tung oil-based isocyanate prepolymer, in order to prepare bio-based reversible cross-linked flame-retardant polyurethane elastomer. The structural composition of obtained polyurethane elastomer is controlled by adjusting the curing process, and its relationship with flame retardant and mechanical properties is clarified. In addition, the relationship between flame retardant and mechanical properties is established to obtain the material with both excellent flame retardant and mechanical properties. Meanwhile, the reversibility of urethane aryl ester bond can realize the recyclability of the polyurethane elastomer. The research of this project will develop a new method for preparing high-performance bio-based flame retardant polyurethane elastomer with potential application value, and will provide new research ideas for promoting the high-value utilization of traditional forest resources.