Synthesis and Properties of Multibranched and Cylindrical Polymers via Living Radical Polymerization of Miner

本项目的目的是通过活性自由基机理研究超支化大分子和纳米柱的结构和性质。主要研究结果如下：1.以甲基丙烯酸2-（N，N-二乙基二硫代氨基甲酰基）乙酯（引发剂：DTEM）和甲基丙烯酸乙酯（EMA）为单体，在紫外光照射下进行活性自由基共聚合，制备了超支化聚甲基丙烯酸乙酯（PEMA）。两种单体对两种增长物种表现出几乎相等的反应性，并且共聚物组成与共聚单体进料相同。这一结果意味着超支化分子的支化和链长都可以通过进料单体比例进行统计控制。研究了超支化PEMA在苯中形成的活性。我们在此聚合体系中进行了一级时间转换图，并且在半对数坐标中的直线表示单体的一级。结果表明，自由基聚合是以活性自由基机理进行的。我们处理的动力学的起始和传播步骤，使用模型化合物。结果，使用这样的速率常数，支化度估计为0.5。以N，N-二乙基二硫代氨基甲酰基甲基苯乙烯（DTCS）为原料，制备了侧链氨基甲酸酯（DC）聚苯乙烯。随后，在紫外光照射下进行DTCS在这种功能化PS上的光接枝聚合。该产物在侧基处具有超支化结构。由于主链在溶液中被拉伸，形成纳米柱。

The aim of this project is to study the architecture and properties of hyperbranched macromolecules and nanocylinders via living radical mechanism. The results obtained as follows.1. Hyperbranched poly (ethyl methacrylate)s (PEMA) were prepared by living radical copolymerization of 2-(N,N-diethyldithiocarbamyl)ethyI methacrylate (inimer : DTEM) with EMA under UV irradiation. Two monomers showed the almost equal reactivity toward both propagating species, and the copolymer composition was the same as the comonomer feed. This result means that both the branching and chain length of the hyperbranched molecules can be controlled statistically by the feed monomer ratios.2. We studied the living nature on the formation of hyperbranched PEMA in benzene. We performed the first-order time-conversion plots in this polymerization system, and the straight line in the semilogarithmic coordinates indicated first order in monomer. It was concluded that free radical polymerization proceeded with living radical mechanism. We treated the kinetics on initiation and propagation steps using model compounds. As a result, the degree of branching was estimated to be 0.5 using such rate constants.3. Polystyrene having pendant carbamate (DC) groups was prepared by (N,N-diethyldithiocarbamyl)-methylstyrene (DTCS). Subsequently, photograft-polymerization of DTCS on such functionalized PS was carried out under UV irradiation. This product exhibited hyperbranched structure at the side group. As the main chain was stretched and behaived as nanocylinder in solution.