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

本项目旨在通过活自由基机制研究超支化大分子和纳米柱的结构和性质。研究结果如下：以2-（N，N-二乙基二硫代氨基甲酸乙酯）甲基丙烯酸乙酯（DTEM）与甲基丙烯酸乙酯（EMA）为共聚物，在紫外辐照下制备了超支化聚甲基丙烯酸乙酯（PEMA）。两种单体对两种繁殖物种的反应性几乎相同，共聚物组成与单体原料相同。这意味着超支化分子的支链和链长都可以通过进料单体比进行统计控制。研究了苯中超支化PEMA生成的活性性质。我们对聚合体系进行了一阶时间转换图，半对数坐标上的直线表示单体的一阶。结果表明，自由基聚合是以活自由基机理进行的。我们用模型化合物处理了起始和扩散过程的动力学。结果，使用这样的速率常数，分支度估计为0.5。采用（N，N-二乙基二硫代氨基甲酸酯）-甲基苯乙烯（DTCS）法制备了氨基甲酸酯悬垂聚苯乙烯（DC）。随后，在UV照射下，在这种功能化的PS上进行了DTCS的光接枝聚合。该产物在侧基上表现出超支化结构。由于主链被拉伸，在溶液中表现为纳米圆柱体。

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.