基于植物油的高交联网络结构水性聚氨酯制备及性能研究

The development of water-borne polyurethanes from natural resource and their derivatives become an important part for sustainable production of polymeric materials and replacement of petroleum-based counterparts attributable to the depletion of the world crude oil stock and environmental concerns. Vegetable oils have been widely used to produce polyols for polyurethanes due to their low price and readily availability. However, the present vegetable oil based water-borne polyurethane coatings demonstrate low water resistance and poor mechanical properties due to low cross-linking densities and existence of hydrophilic groups in their polymer chains. In this proposal, bio-based high functionality polyols with primary hydroxyl groups are developed from typical vegetable oils through structural design and controllable polymerization; then water-borne polyurethane nano-composites with high cross-linking densities and chemical-bonding silica are prepared from the above polyols. The effect of high functionality polyols with long fatty acid chains and nano-silica on the thermal resistance, water resistance and mechanical properties of the resulting polyurethanes are investigated and discussed. The objective of this proposal is to explore new pathway and new method to prepare vegetable oil based polyurethanes and lay the foundation for the scalable application of water-borne polyurethanes in the area of leather treatment agents, adhesives, and organic coatings.

以天然产物及其衍生物等可再生资源为基础合成水性聚氨酯具有节约能源和环境保护的多重功效，是实现高分子材料可持续发展和替代溶剂型树脂的的一个重要方向。植物油由于来源广泛和价格低廉已经作为一种重要原料广泛应用于聚氨酯多元醇的合成。但是目前植物油基水性聚氨酯涂膜交联密度不高以及分子链本身亲水基团的存在使其涂膜的耐水性、力学等性能不足，限制其应用。本项目拟从典型的植物油出发，通过结构设计与可控聚合制备高官能度伯羟基化生物基多元醇；进而构建含有化学键合的纳米二氧化硅的具有高交联网络结构的水性聚氨酯-无机杂化体系；探讨高官能度长脂肪酸链多元醇和纳米二氧化硅的引入对水性聚氨酯耐热性、耐水性、拉伸强度及断裂伸长率等性能的影响；并揭示其组成、结构与性能之间的关系，探索植物油基水性聚氨酯材料合成的新思路和新方法，为拓宽水性聚氨酯在皮革处理剂、胶粘剂以及工业涂料等领域的应用奠定基础。

本项目以大豆油和亚麻籽油出发，通过自催化环氧/开环法和巯基-烯光点击法，制备了全生物基多元醇和水性扩链剂，进一步通过本体预聚和溶液分步多次聚合法构建含有非极性长脂肪酸链和高交联密度的水性聚氨酯体系；最后通过引入无机纳米增强相提高聚氨酯的交联密度和调控表面拓扑形貌，最终形成植物油基聚氨酯-无机杂化涂膜，其耐水性和力学性能媲美溶剂型水性聚氨酯材料。揭示了植物油活性位点的区域选择性与化学选择性对化学转化历程和效率的调控机理；阐明非极性长脂肪酸链结构单位、聚合条件对形成聚氨酯凝胶的影响规律；明确水性聚氨酯功能基元与乳液结构特征及其涂膜性能之间的构效关系，也为新型水性聚氨酯材料的设计和合成提出理论基础和指导。通过本项目的资助，在Angewandte Chemie International Edition, Green Chemistry，ACS Applied Materials and interfaces等化学和材料高水平期刊上发表SCI论文15篇，申请发明专利5项。培养硕士研究生4人。