We discovered unique solution properties, including cosolvency of an amphiphilic alternating copolymer comprising hydrophobic N-ethylmaleimide (EMIm) and hydrophilic 2-hydroxyethyl vinyl ether (HEVE). The solubility of polymers is greatly affected by the balance of polymer–polymer interaction and polymer–solvent interaction, and an amphiphilic alternating sequence is attractive for achieving unique solubility. We synthesized the alternating copolymers P(EMIm/HEVE) by reversible addition-fragmentation chain transfer polymerization to investigate the solubility in a variety of solvents. The obtained polymers exhibited the upper-critical-solution-temperature-type miscibility behavior in various alcohols, and the insoluble-to-soluble transition temperature varied depending on the alcohol structure: bulkier and more hydrophobic alcohol resulted in a higher transition temperature. Furthermore, P(EMIm/HEVE) was shown to be soluble in the mixture of ethanol and water, despite being insoluble in each solvent at room temperature. This cosolvency phenomenon was probably due to the change in the local composition of ethanol and water around the polymer.

中文翻译：

---

N-乙基马来酰亚胺和2-羟乙基乙烯基醚的两亲性交替共聚物的溶液性质：醇中的热响应性和二元乙醇/水溶液中的共溶剂现象

我们发现了独特的溶液特性，包括包含疏水性N-乙基马来酰亚胺 (EMIm) 和亲水性 2-羟乙基乙烯基醚 (HEVE)的两亲性交替共聚物的共溶剂性。聚合物的溶解度很大程度上受到聚合物-聚合物相互作用和聚合物-溶剂相互作用的平衡的影响，并且两亲性交替序列对于实现独特的溶解度具有吸引力。我们通过可逆加成断裂链转移聚合合成了交替共聚物P(EMIm/HEVE)，并研究了其在多种溶剂中的溶解度。所得聚合物在各种醇中表现出上临界溶液温度型混溶行为，并且不溶到可溶的转变温度根据醇结构而变化：体积较大且疏水性更强的醇导致更高的转变温度。此外，P(EMIm/HEVE) 显示可溶于乙醇和水的混合物，尽管在室温下不溶于每种溶剂。这种共溶剂现象可能是由于聚合物周围乙醇和水的局部成分发生变化所致。