Cationic bottlebrush homopolymers are polymerized using a grafting‐through approach by ring‐opening metathesis polymerization (ROMP) to afford well‐defined polymers. Quaternary ammonium macromonomers (MMs) are prepared by quaternizing tertiary amine MMs synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization. The quaternary ammonium MMs undergo ROMP to target molecular weights (M_n = 30 000–100 000 g mol⁻¹) and a low dispersity (Đ = 1.10–1.30). Halide‐ligand exchange between the third generation Grubbs catalyst (G3) and halide counter ions (bromide and iodide ions) of MMs changes the catalyst activity throughout ROMP, causing it to deviate from pseudo‐first order kinetic behavior; however, the polymerization still follows controlled behavior without significant catalyst termination. Increasing steric bulk of the MMs decreases the polymerization rate as well. Amphiphilic block copolymers are synthesized by sequential polymerization of quaternary ammonium MMs and polystyrene (PS) MMs. Using a PS macroinitiator affords block copolymers with lower Đ values as compared to the less active cationic macroinitiator.

中文翻译：

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季铵盐大单体通过接枝开环复分解聚合反应制得的阳离子瓶刷聚合物

通过开环易位聚合（ROMP），通过接枝方法聚合阳离子瓶刷均聚物，得到定义明确的聚合物。季铵大分子单体（MMs）是通过将可逆加成-断裂链转移（RAFT）聚合合成的叔胺MMs季铵化而制备的。季铵MM经过ROMP达到目标分子量（M _n = 30 000–100 000 g mol ^-1）和低分散性（Đ= 1.10–1.30）。第三代Grubbs催化剂（G3）与MM的卤化物抗衡离子（溴化物和碘化物离子）之间的卤化物交换会改变整个ROMP的催化剂活性，从而使其偏离拟一级动力学行为。然而，聚合反应仍然遵循受控的行为，而没有明显的催化剂终止。MM的空间体积增加也降低了聚合速率。两性嵌段共聚物是通过季铵MM和聚苯乙烯（PS）MM的顺序聚合合成的。与活性较低的阳离子大分子引发剂相比，使用PS大分子引发剂可提供具有更低Đ值的嵌段共聚物。