瑞士苏黎世联邦理工学院Athina Anastasaki研究团队报道了可见光下酸增强光干扰素聚合。相关研究成果于2024年12月25日发表在《德国应用化学》。

光引发剂（PI）是一种有前景的聚合方法，通常用于克服热可逆加成断裂链转移（RAFT）聚合的限制。然而，在绝大多数研究中，需要高能紫外线照射才能有效触发RAFT试剂的光解并促进聚合，这大大限制了其潜力、范围和适用性。

尽管可见光PI已成为一种极具吸引力的替代品，但目前的大多数方法仅限于合成较低分子量的聚合物，并且通常存在反应时间延长、诱导期延长和分散性提高的问题。

该文介绍了一种在可见光照射下高效运行的酸增强PI RAFT聚合的方法。少量生物相容性柠檬酸的存在通过增强光解作用，完全消除了漫长的诱导期，快速消耗CTA，加速了反应速率，产生了摩尔质量分布窄、转化率接近定量、端基保真度高的聚合物。也可以在短时间内合成超高分子量聚合物，而不会影响对分散性的控制（D~1.1）。

研究人员通过合成定义明确的二嵌段共聚物，及其与各种聚合物类别（即丙烯酰胺、丙烯酸酯、甲基丙烯酸酯）的相容性，进一步证明了该技术的多功能性，从而将可见光PI确立为聚合物合成的稳健工具。

附：英文原文

Title: Acid-Enhanced Photoiniferter Polymerization under Visible Light

Author: Maria-Nefeli Antonopoulou, Nghia P. Truong, Timon Egger, Asja A. Kroeger, Michelle L. Coote, Athina Anastasaki

Issue&Volume: 2024-12-25

Abstract: Photoiniferter (PI) is a promising polymerization methodology, often used to overcome restrictions posed by thermal reversible addition-fragmentation chain-transfer (RAFT)  polymerization. However, in the overwhelming majority of reports, high energy UV irradiation is required to effectively trigger photolysis of RAFT agents and facilitate the polymerization, significantly limiting its potential, scope, and applicability. Although visible light PI has emerged as a highly attractive alternative, most current approaches are limited to the synthesis of lower molecular weight polymers, and typically suffer from prolonged reaction times, extended induction periods, and higher dispersities. Herein, an acid-enhanced PI RAFT polymerization is introduced that efficiently operates under visible light irradiation. The presence of small amounts of biocompatible citric acid fully eliminates the lengthy induction period by enhancing photolysis, rapidly consumes the CTA, and accelerates the reaction rate, yielding polymers with narrow molar mass distributions, near-quantitative conversions, and high end-group fidelity. Ultra-high  molecular weight polymers can also be synthesized within short timescales without compromising the control over the dispersity (D ~1.1). The versatility of the technique is further demonstrated through the synthesis of well-defined diblock copolymers and its compatibility to various polymer classes (i.e. acrylamides, acrylates, methacrylates), thus establishing visible-light PI as a robust tool for polymer synthesis.

DOI: 10.1002/anie.202420733

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202420733