Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States.
J Am Chem Soc. 2021 Mar 10;143(9):3318-3322. doi: 10.1021/jacs.1c00561. Epub 2021 Feb 27.
Precision synthesis of cyclic polymers with predictable molecular weight and low dispersity is a challenging task, particularly concerning cyclic polar vinyl polymers through a rapid chain-growth mechanism and without high dilution. Harder yet is the precision synthesis of cyclic block copolymers (BCPs), ideally from comonomer mixtures. Here we report that Lewis pair polymerization (LPP) capable of thermodynamically and kinetically compounded sequence control successfully addressed this longstanding challenge. Thus, LPP of acrylate/methacrylate mixtures under ambient temperature and normal concentration conditions rapidly and selectively affords well-defined BCPs with high molecular weight ( = 247 kg/mol) and low dispersity ( = 1.04) in one step. Such BCPs have been characterized by multiple techniques, including direct structural observation by imaging.
精确合成具有预测分子量和低分散度的环状聚合物是一项具有挑战性的任务，特别是通过快速链增长机制且不在高稀释条件下合成环状极性乙烯基聚合物。更具挑战性的是环状嵌段共聚物（BCP）的精确合成，理想情况下是由共聚单体混合物合成。在这里，我们报告说，路易斯对聚合（LPP）能够通过热力学和动力学复合序列控制成功解决了这一长期存在的挑战。因此，在环境温度和正常浓度条件下，LPP 快速且选择性地聚合丙烯酸酯/甲基丙烯酸酯混合物，一步法即可得到具有高分子量（=247kg/mol）和低分散度（=1.04）的高度确定的 BCP。这些 BCP 已经通过多种技术进行了表征，包括通过成像直接进行结构观察。
