基于桐油/松香的自修复聚氨酯动态可逆交联网络构建及调控机制

我国林业特色资源松香和桐油高附加值利用率低，开辟高端应用新领域迫在眉睫；本项目拟以松香、桐油等为原料，采用Diels-Alder加成、Friedel-Crafts烷基化等手段引入热可逆酚型氨酯键和氢键制备一系列结构新颖的软硬单体和动态交联网络自修复聚氨酯材料；着重考察材料自修复时吸放热行为、结构化学位移、分子量分布等热可逆特征及修复后形貌和性能变化，探明官能团定向转化机制，松香刚性菲环、桐油柔性长链及天然酚含量，软硬段比例，热可逆键引入等对材料结构、性能影响规律及双重自修复协同机理等科学问题，获得具有高生物质含量、高自修复率和优良力学性能的聚氨酯材料有效制备方法；本研究将进一步拓展林产资源高效化学转化理论体系，为林产资源高值化和高分子材料循环利用开辟新的途径。

Rosin and tung oil are important and abundant forest products in China. Both are used in a wide variety of applications, but their high-value utilization still remains at a relatively low level. It is necessary to explore other higher value products. In this project, a series of rosin- and tung oil-based soft and hard monomers and dynamic crosslinking network self-healing polyurethane with novel structures will be prepared by Diels-Alder addition, Friedel-Crafts alkylation and other methods, while the self-healing mechanism is introduced through phenolic urethane bonds and hydrogen bonds, which both with the thermoreversible characteristic. The objectives of this project include: 1) investigate the thermoreversible characteristics such as heat absorption and exothermic behavior, structural chemical shift, molecular weight distribution, etc., and changes in morphology and performance after repair; 2) explore the scientific problems such as the oriented conversion mechanism of functional groups, the content of the rigid phenanthrene ring of rosin, the flexible long chain of tung oil and natural phenols, the proportion of soft and hard segments, the introduction of thermoreversible bonds on the structure and performance of polyurethane, and the synergetic mechanism of double self-healing; 3)obtain an effective preparation method of polyurethane with high biomass content, high self-healing rate and excellent mechanical properties. This research will further expand the theoretical system of efficient chemical conversion of forest products and open up new ways for the high-value utilization of forest products and recycling of polymer materials.