Kimura Taichi, Kuroda Keita, Kubota Hiroyuki, Ouchi Makoto
Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.
ACS Macro Lett. 2021 Dec 21;10(12):1535-1539. doi: 10.1021/acsmacrolett.1c00601. Epub 2021 Nov 16.
In this work, we achieved switching degradation of vinyl polymers made of a carbon-carbon bonded backbone. Crucial in this strategy was a small feed of methyl α-chloroacrylate (MCA) as the comonomer in radical polymerization of methyl methacrylate (MMA) so that the carbon-halogen bonds were introduced as the triggers for degradation. The "in-chain" trigger was activated by a one-electron redox metal catalyst as the chemical stimulus to generate the carbon-centered radical species, and subsequently, the neighboring carbon-carbon bond was cleaved via an electron transfer of the radical species giving the terminal olefin. Particularly, an iron complex (FeCl) in conjunction with tributylamine (-BuN) was effective as the chemical stimulus to allow the switching degradation, where the molecular weight was gradually decreased over time. The switching feature was confirmed by some control experiments.
在这项工作中，我们实现了由碳 - 碳键主链构成的乙烯基聚合物的开关式降解。该策略的关键在于，在甲基丙烯酸甲酯（MMA）的自由基聚合反应中，加入少量的α - 氯丙烯酸甲酯（MCA）作为共聚单体，从而引入碳 - 卤键作为降解的触发因素。“链内”触发因素由单电子氧化还原金属催化剂作为化学刺激激活，以产生碳中心自由基物种，随后，相邻的碳 - 碳键通过自由基物种的电子转移断裂，生成末端烯烃。特别地，铁配合物（FeCl）与三丁胺（-BuN）结合作为化学刺激，能够实现开关式降解，在此过程中分子量随时间逐渐降低。通过一些对照实验证实了这种开关特性。
