Synthesis and Surface Formation of Three-Component Graft Copolymers

本研究旨在获得柔性高分子材料表面独特的环境响应行为的新见解。从生物工程到摩擦学等先进应用领域，多组分聚合物分子的节段拓扑结构的精确设计是实现前所未有的功能的先决条件。我们首先研究了三组分共聚物体系的表面形成和环境响应行为。因此，我们合成了PVA（聚乙烯醇）和PU（聚氨酯）为基础的三组分体系，即PVA或PU为主链段，PS（聚苯乙烯）-嵌段PDMS（聚二甲基硅氧烷）为接枝段，其中三个链段的几何排列与其表面能的顺序相反，即PVA（或PU） >PS>PDMS。在两种相互冲突的驱动力作用下形成的表面表现出独特的环境响应，即接触介质由空气变为水。我们还设计了一种新的聚合物反应工艺，利用自组装原理来预先组织大分子组分，然后将它们转化为永久的聚合物结构。因此，吡咯吡啶盐端基的静电自组装和随后的共价固定能力的独特特性已被应用于制备拓扑独特的支链聚合物、环状聚合物和网状聚合物。具有环鎓盐基团的单官能远螺旋与具有适当亲核反应活性的多官能羧酸盐进行了简单共沉淀，得到了相应的星形和梳状聚合物；双官能远螺旋与双官能羧酸盐进行了简单共沉淀，在稀释溶液中分别得到了环状聚合物以及缩合相中的延伸链“节段”聚合物和“模型网络”聚合物。

The present study has aimed to obtain new insights for the environmental response behavior, unique to flexible polymer materials surfaces. The precise design with respects to the segment topology of multicomponent polymer molecule is a prerequisite for unprecedented functions required in advanced application fields from bioengineering to tribology.We have first examined on the surface formation and environmental response behavior on three-component copolymer systems. Thus we have synthesized PVA (polyvinyl alcohol) and PU (polyurethane) -based three-component systems, i.e.PVA or PU as the main chain segment and PS (polystirene) -block-PDMS (polydimethylsiloxane) as a graft segment, in which the geometrical arrangement of the three segments is inverse to the order of their surface energies, i.e.PVA (orPU) >PS>PDMS.The surface formed under the influence of the two conflicting driving forces exhibited unique environmental response by the change of the contacting medium from air to water.We have also designed a new polymer reaction process by making use of self-assembly principle in order to pre-organize macromolecular components, and subsequently converting them into permanent polymer arcitectures. Thus a unique feature, i.e.electrostatic self-assembly and subsequent covalent fixation capability, of the pyrrolidinium salt end groups has been applied for the preparation of topologically-unique, branched polymers, ring polymers and network polymers. The simple coprecipitation of the monofunctional telechelics having a cyclic onium salt group with plurifunctional carboxylates of appropriate nucleophilic reactivities has been carried out to produce the corresponding star- and comb-shaped polymers, and that of bifunctional telechelics with bifunctional carboxylate leading to the ring polymers in a diluted solution as well as the chain-extended "segmented" polymers and "model-network" polymers in a condensed phase, respectively.