Treat Nicolas J, Fors Brett P, Kramer John W, Christianson Matthew, Chiu Chien-Yang, Read de Alaniz Javier, Hawker Craig J
The Dow Chemical Company, Midland, Michigan 48674, United States.
ACS Macro Lett. 2014 Jun 17;3(6):580-584. doi: 10.1021/mz500242a. Epub 2014 Jun 2.
The controlled radical polymerization of a variety of acrylate monomers is reported using an Ir-catalyzed visible light mediated process leading to well-defined homo-, random, and block copolymers. The polymerizations could be efficiently activated and deactivated using light while maintaining a linear increase in molecular weight with conversion and first order kinetics. The robust nature of the -[Ir(ppy)] catalyst allows carboxylic acids to be directly introduced at the chain ends through functional initiators or along the backbone of random copolymers (controlled process up to 50 mol % acrylic acid incorporation). In contrast to traditional ATRP procedures, low polydispersity block copolymers, poly(acrylate)--(acrylate), poly(methacrylate)--(acrylate), and poly(acrylate)--(methacrylate), could be prepared with no monomer sequence requirements. These results illustrate the increasing generality and utility of light mediated Ir-catalyzed polymerization as a platform for polymer synthesis.
据报道，使用铱催化的可见光介导过程可实现多种丙烯酸酯单体的可控自由基聚合，从而得到结构明确的均聚物、无规共聚物和嵌段共聚物。聚合反应可通过光有效地激活和失活，同时分子量随转化率呈线性增加，并具有一级动力学特征。-[Ir(ppy)]催化剂的稳健性质使得羧酸能够通过功能性引发剂直接引入链端，或沿着无规共聚物的主链引入（在丙烯酸掺入量高达50摩尔%时为可控过程）。与传统的原子转移自由基聚合（ATRP）方法不同，无需单体序列要求即可制备低多分散性的嵌段共聚物，如聚（丙烯酸酯）-b-（丙烯酸酯）、聚（甲基丙烯酸酯）-b-（丙烯酸酯）和聚（丙烯酸酯）-b-（甲基丙烯酸酯）。这些结果表明，光介导的铱催化聚合作为一种聚合物合成平台，其通用性和实用性日益增强。
