Typical cyclic diblock polymers are synthesized from their linear precursors via the ring-closure strategy in dilute conditions. Here we demonstrate a pseudo-high-dilution condition strategy for the efficient synthesis of cyclic rod–coil diblock copolymer from its linear precursor in selective solvents. The critical association concentration (CAC) of linear precursor is used for the control of unimer concentration during cyclization, while high copolymer synthetic concentrations are achieved via the dynamic equilibrium between unimers and micelles. The effects of CAC and micelle concentration on cyclization yield are studied and pure cyclic rod–coil diblock copolymer was obtained after azide resin treatment. Property investigations show the cyclic rod–coil copolymer has a larger second virial coefficient than its linear counterpart and self-assembles in selective solvents to form larger but looser spherical micelles due to its constraint topological structure.

中文翻译：

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环状棒-线圈二嵌段共聚物的合成及溶液自组装性能

典型的环状二嵌段聚合物是由它们的线性前体在稀释条件下通过闭环策略合成的。在这里，我们展示了一种伪高稀释条件策略，用于在选择性溶剂中从其线性前体有效合成环状棒 - 线圈二嵌段共聚物。线性前体的临界缔合浓度 (CAC) 用于控制环化过程中的单聚体浓度，而高共聚物合成浓度是通过单聚体和胶束之间的动态平衡来实现的。研究了CAC和胶束浓度对环化收率的影响，经叠氮树脂处理后得到纯环状棒-螺旋二嵌段共聚物。