基团调控耐水解聚醚有机硅表面活性剂的设计、合成及机理研究

With excellent performance, Non-ionic polyether silicone surfactant (PESS) has a significant potential application in academic research and industrial production. PESS products are found not stable, resulted in structure damage via the hydrolysis progress in non-neutral solvents. Therefore, it is very important to realize the efficient synthesis of hydrolysis-resistant non-ionic PESS. In our team’s preliminary work, the heterogeneous catalytic preparation process of PESS has been developed. And it was found that the regioselectivity of hydrosilylation was controlled by both substrates and catalysts. At the same time, the molecular structure had an important influence on the stability of the product in the solution. However, the mechanism of both the regioselectivity and hydrolysis progress are not yet clear. .In view of the above scientific issues, this project focuses on obtaining structure and performance data of the products via molecular design by computational chemistry, preparation of PESS compounds, and characterization techniques such as on-line NMR and contact angle measurement. And then, the influence of molecular structures and electron properties on regioselectivity of hydrosilylation will be explored. The relationship between product stability and molecular structure will also be investigated. After that, the general rules of controlling regioselectivity of hydrosilylation and hydrolysis of products will be found. These research achievements will provide solid foundation for solving the stability problem of nonionic polyether silicone surfactants, and afford theoretical guidance for the development of hydrolysis-resistant polyether silicone pesticides.

非离子型聚醚有机硅表面活性剂（PESS）性能优异，在科学研究和工农业生产领域具有很好的应用前景。目前PESS产品存在在非中性环境易水解、表面活性物质结构受损等问题，因此实现耐水解非离子型PESS的高效合成具有重要意义。本团队前期发展了非均相催化PESS的制备工艺，发现硅氢加成的选择性受到底物基团和催化剂的双重控制，同时分子结构对产品在溶液中的稳定性具有重要影响，但是其选择性调控机制和水解规律均不明确。.针对以上科学问题，本项目拟采用量化计算辅助分子设计，合成一系列PESS分子，结合在线核磁、接触角测试等表征技术，获得产物结构证据和性能指标，探究并阐明不同催化体系基团导向对氢硅化的选择性调控机制，揭示产品稳定性和分子结构的构效关系，提出基团调控硅氢加成和产物水解机制的共性规律。本项目有望为解决非离子型PESS的稳定性问题奠定科学基础，为耐水解聚醚有机硅农药增效助剂的开发提供理论指导。

本项目针对非离子型聚醚有机硅表面活性剂合成中硅氢加成选择性调控机制和水解规律不明确等问题，开展了过渡金属催化基团取代硅烷和烯烃的硅氢加成的基础研究。在项目执行中系统的探究了不同催化体系对APEG-380和MDHM硅氢加成反应的选择性调控机制，实现了耐水解、超浸润的聚醚有机硅表面活性剂的高效合成，获得了基团结合催化剂调控硅氢加成区域选择性的导向规律；也通过取代基调变和取代位点变更合成不同硅烷和烯烃，在更多新结构耐水解聚醚有机硅表面活性剂的合成中进行了诸多尝试，但由于基团效应等的影响，硅氢加成反应中聚醚有机硅表面活性剂的选择性不佳，大位阻基团的存在会提高目标产物的耐水解性能，但其超浸润性能受到了明显影响。.基于原料合成与反应尝试过程中的意外发现，发展了1）室温下可自修复的高强度硬质材料P(AamKH550)/PVA；2）NHPI催化低碳烯烃温和条件下的需氧高选择性环氧化；3）过渡金属催化烯烃高选择性环氧化。环氧化物尤其是环氧丙烷和环氧丁烷是重要的基础有机化工原料，广泛应用于生产聚醚多元醇、非离子表面活性剂等轻工产品，但目前烯烃催化环氧化存在着环境不友好、选择性差等问题，因此实现烯烃的高效环氧化具有显著意义。在本项目的探索中尤其为烯烃催化转化领域开发了一系列新型催化剂，实现了烯烃尤其是非活化烯烃的高选择性环氧化。并通过电子顺磁共振、高分辨质谱、原位红外等表征手段，结合动力学和同位素实验，阐明了反应历程中自由基活性中间体的产生和传递调控机制，揭示了影响烯烃环氧化选择性控制的关键影响因素。这些研究成果将为新催化剂的设计开发提供新思路，为深入探索烯烃催化氧化理论研究提供更充分的科学依据，也为催化氧化过程放大和工业应用提供理论和技术基础。