DESIGN AND APPLICATION OF AMPHIPHILIC ORGANIZED POLYMERS BY POLYMERIZATION OF SUFACE-ACTIVE MONOMERS

本研究旨在利用两亲性大分子单体设计具有两亲性的有机聚合物。制备了带有苯乙烯或甲基丙烯酸酯端基的聚环氧乙烷（PEO）和聚甲基丙烯酸（PMA）大分子单体，并通过烯基间隔基增强疏水性。发现这些大分子单体在水中非常迅速地聚合，得到具有疏水主干和亲水分支的规则梳形聚合物，并且与疏水单体在水或醇介质中共聚，得到亚微米至微米尺寸的受控聚合物微球。本课题揭示了两亲性大分子单体在水中胶束聚合的基本机理，对规则且密集支化的梳形聚合物的构象进行了表征，并为利用两亲性大分子单体设计聚合物微球提供了基本指导。主要结论如下。(1)研究了PEO大分子单体在水中的快速聚合反应， ...更多信息 动力学上通过使用ESR等，归因于它们的胶束形成。在水中得到的梳状聚合物可以被描述为半柔性蠕虫状链，就像具有硬的疏水聚苯乙烯轴的瓶刷，具有大量的软的可溶性PEO毛，其将发挥广泛的排除体积效应。(2)在苯乙烯和甲基丙烯酸丁酯的甲醇-水分散聚合中，PEO大分子单体有效地得到了亚微米至微米级的单分散微球。基于覆盖在表面上的接枝共聚的大分子单体链的空间稳定性的粒度控制理论合理地解释了实验;尺寸根据转化率的1/3阶、共聚单体浓度的2/3阶和大分子单体浓度的-1/2阶而变化。接枝PEO链从无规卷曲到延伸构象的变化也通过NMR测量证实。(3)PEO和PMA大分子单体在苯乙烯的乳液聚合中也是有效的。传统的乳液聚合理论必须加以修正，以考虑大分子单体除了作为乳化剂外，还参与了共聚反应，表面活性大分子单体可用于设计高分子两亲物，包括规则梳型聚合物和微球，具有广泛的应用前景。少

This research project aimed at design of amphiphilically organized polymers by taking advantage of amphiphilic macromonomers. Poly(ethylene oxide) (PEO) and poly(methacrylic acid) (PMA) macromonomers carrying styry1 or methacrylate end groups, hydrophobically enhanced by alkylene spacers, were prepared. These macromonomers were found to polymerize very rapidly in water to afford regular comb polymers with hydrophobic trunks and hydrophilic branches, and copolymerize with a hydrophobic monomer in water or alcoholic media to give controlled polymeric microsheres of submicron to micron size. This project has thus disclosed a basic mechanism of micellar polymerization of these amphilic macromonomers in water, conformational characterization of regularly and densely branched comb polymers, and a fundamental guideline to the polymeric microspheres' design using amphiphilic macromonomers. The main conclusions follow.(1) Very rapid polymerization of the PEO macromonomers in water was studied k … More inetically by use of ESR among others, to be ascribed to their micelle formation. The resulting comb polymer in water could be described as a semiflexible wormlike chain just like a bottlebrush with a hard, hydrophobic polystyrene axle with voluminous number of soft, soluble PEO hairs which will exert an extensive excluded-volume effect.(2) The PEO macromonomers effectively afforded monodisperse microspheres of submicron to micron size in dispersion polymerization of styrene and butyl methacrylate in methanol-water. A theory of particle size control, based on the steric stabilization by the graft-copolymerized macromonomer chains covered on the surface, reasonably accounted for the experiments ; the size changes according to 1/3rd order of conversion, 2/3rd order of the comonomer concentration, and -1/2nd order of the macromonomer concentration. Change of the grafted PEO chains from a random coil to an extended conformation was also confirmed by NMR measurement.(3) PEO and PMA macromonomers were also effective in emulsion polymerization of styrene. The traditional theory of emulsion polymerization has to be modified to account for the macromonomers to take part in the copolymerization in addition to function as the emulsifiers.To summarize, the surface-active macromonomers are useful for design of polymeric amphiphiles including regular comb polymers and microspheres, promising a variety of applications. Less