安徽农业大学袁亮小组在高分子化学的研究中取得进展。他们报道了无引发剂的巯基醛光缩聚。2025年1月2日，国际知名学术期刊《德国应用化学》发表了这一成果。

在这项工作中，该课题组发现了一个在聚合物和醛单体之间无引发剂的光缩聚体系（IFPPC），生产具有可交换和可降解的二硫缩醛基团的高强度塑料材料。IFPPC通过自由基机制进行，适用于生产线性聚合物和交联网络。他们还以纤维素纳米纤维为稳定剂，采用有机无溶剂皮克林乳液聚合法制备纳米复合材料。

二硫缩醛基团在水解条件和交联聚合物的反复热处理下具有优异的稳定性，而它们在盐类（硝酸银、碘化锌、溴化铜等）的水溶液中降解速度快，可回收乙醛单体。这是一个通过光照射生产可回收和可降解塑料的成功示范，同时避免了光引发剂的问题。

据悉，传统的光聚合通常需要引发剂来引发聚合，而很少有情况下产生可降解的化学键。此外，光引发剂的迁移不稳定性和细胞毒性对人类健康和环境构成了威胁。

附：英文原文

Title: Initiator-Free Thiol-Aldehyde Photo Polycondensation

Author: Liang Yuan, Wangmao Tian, Jie Wang, Yu Jin, Yaming Cheng, Kangle Yan, Chengcheng Hu, Cheng Chen, Baoxia Wang, Zhongkai Wang

Issue&Volume: 2025-01-02

Abstract: Traditional photopolymerizations generally requires an initiator for initiating the polymerization while few cases have created degradable chemical bonds. Moreover, the migration instability and cytotoxicity of photo initiators are posing issues to human health and the environment. In this work, we discovered an initiator-free photo polycondensation system (IFPPC) between polymercaptans and aldehyde monomers, producing high strength plastic materials with exchangeable and degradable dithioacetal groups. IFPPC proceeds through a radical mechanism and is applicable in producing linear polymers and crosslinked networks. Nano-composites can also be obtained via an organic solvent-free Pickering emulsion polymerization using cellulose nanofibers as the stabilizer. The dithioacetal groups afford excellent stability under hydrolytic conditions and repeated thermal processing of cross-linked polymers, while their cleavage in aqueous solution of salts (silver nitrate, zinc iodide, copper bromide, etc.) results in fast degradation for recovering the aldehyde monomer. This is a successful demonstration of producing recyclable and degradable plastics through photo irradiation while avoiding the problematic issues of photo initiators.

DOI: 10.1002/anie.202421231

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202421231