基于有机分子催化基团转移聚合的丙烯酸类聚合物末端官能化的基础性研究及其拓展

Functional silyl ketene acetal is prepared through the in situ 1,4-hydrosilylation of functional cinnamate (or other analogous compounds) with a hydrosilane using organocatalyst, tris(pentafluorophenyl)borane, in organic solvent. To the above mixture solution an acrylic monomer is added to implement its tris(pentafluorophenyl)borane-catalyzed group transfer polymerization, through which the initiation end functionalized acrylic polymer can be obtained. On the other hand, based on the nature that the trisubstituted silyl group of the silyl ketene acetal moiety at the propagating end is prone to transfer from the Si-O bond (silyl enolate structure) to the Si-C bond (alpha-trialkylsilyl ketone structure) during the late stage of a group transfer polymerization process, it is promising to realize the synthesis of the termination end functionalized acrylic polymer by first designing a functional hydrosilane and consequently carrying out the the tris(pentafluorophenyl)borane-catalyzed group transfer polymerization of an acrylic monomer. By conprehensively applying the two synthetic concepts, the synthesis of both initiation and termination end functionalized acrylic polymer can be achieved. The aforediscussed end functionalization method can be further applied to construct other polymer structures with different topologies, such as block copolymers, star-shaped polymers, and brush polymers, as well as other aspects, like acrylic polymer grafting.

以三(五氟苯基)硼烷为有机催化剂，在溶液中通过用氢化硅烷对官能化肉桂酸酯进行1, 4-硅氢化反应以in situ的方式得到官能化硅烷基乙烯酮缩醛。在上述溶液中继续加入丙烯酸类单体可实现对丙烯酸类单体的有机催化基团转移聚合，从而简便合成起始末端官能化的丙烯酸类聚合物。另一方面，利用基团转移聚合中活性末端硅烷基乙烯酮缩醛中的三取代硅基易从Si-O键转移至Si-C的特点，通过对潜在性引发剂氢化硅烷进行官能化的分子设计并将其应用于三(五氟苯基)硼催化的针对丙烯酸酯类单体的基团转移聚合，可简便合成终止末端官能化的丙烯酸类聚合物。综合应用上述两种分子设计理念，即同时应用官能化的肉桂酸酯以及氢化硅烷通过对丙烯酸类单体的有机催化基团转移聚合，可实现起始，终止两末端官能化丙烯酸类聚合物的合成。以上针对丙烯酸类聚合物末端官能化的基础性研究可扩展至嵌段共聚物，星型聚合物，梳状聚合物等具高次拓扑结构聚合物的构筑。

根据项目的研究目标和内容，围绕有机路易斯酸为催化剂，氢化硅烷为潜在性引发剂的丙烯酸衍生类单体的基团转移聚合方法及应用该方法进行丙烯酸类聚合物的末端官能化，我们展开了一系列系统的研究工作并按期完成相关科研任务。展开的研究工作包括：（1）基于有机三（五氟苯基）硼烷为催化剂、氢硅烷为潜在起始物的丙烯酸酯类单体的有机催化基团转移聚合的研究系统研究；（2）基于（1）中方法，深入探讨了各类丙烯酸烷酯及官能性丙烯酸酯的聚合行为；（3）基于上述方法，研究并实现了利用化学性质稳定的 HSiR3 以及肉桂酸类化合物及其类似物，开发新型针对丙烯酸类聚合物的简便实用末端官能化方法。本项目研究完成了预期的内容并达到了预期的目标，为开发利用有机路易斯酸为催化剂的丙烯酸衍生类单体的基团转移聚合及其末端官能化方法奠定了理论和实验基础，并为潜在的工业化应用提供理论指导。