华东理工大学曲大辉团队报道了酸催化二硫介导的可回收动态共价材料可逆聚合。相关研究成果发表在2023年1月5日出版的《德国应用化学》。

聚（1,2-二硫杂环戊烷）由于其动态共价二硫键，是一类本质上可回收的聚合物。尽管在碱性条件下通常使用硫代硫酸盐引发的阴离子开环聚合（ROP），但阳离子ROP仍然没有被开发。

该文中，研究人员报道了二硫键可以作为质子受体，被酸质子化形成锍阳离子，这可以有效地引发1,2-二硫杂环的ROP，并产生高分子量（超过1000kDa）的聚（二硫）。反应可以通过加入催化量的酸和非配位阴离子盐来引发，并在室温下几分钟内完成。酸性条件允许酸性单体的适用性。重要的是，反应条件可以在没有惰性保护的露天条件下进行，从而实现从散装材料到原始单体的几乎定量的化学循环。

附：英文原文

Title: Acid-catalyzed Disulfide-mediated Reversible Polymerization for Recyclable Dynamic Covalent Materials

Author: Bang-Sen Wang, Qi Zhang, Zhi-Qiang Wang, Chen-Yu Shi, Xue-Qing Gong, He Tian, Da-Hui Qu

Issue&Volume: 2023-01-05

Abstract: Poly(1,2-dithiolane)s are a family of intrinsically recyclable polymers due to their dynamic covalent disulfide linkages. Despite the common use of thiolate-initiated anionic ring-opening polymerization (ROP) under basic condition, cationic ROP is still not exploited. Here we report that disulfide bond can act as a proton acceptor, being protonated by acids to form sulfonium cations, which can efficiently initiate the ROP of 1,2-dithiolanes and result in high-molecular-weight (over 1000 kDa) poly(disulfide)s. The reaction can be triggered by adding catalytic amounts of acids and non-coordinating anion salts, and completed in few minutes at room temperature. The acidic conditions allow the applicability for acidic monomers. Importantly, the reaction condition can be under open air without inert protection, enabling the nearly quantitative chemical recycling from bulk materials to original monomers.

DOI: 10.1002/anie.202215329

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202215329