Zhang Longfei, Zou Xiuyang, Ding Chengqiang, Wang Zhao
State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, College of Chemistry, Chemical Engineering and Materials Science, Soochow University Suzhou 215123 China
Jiangsu Province Engineering Research Center of Environment Functional Materials, School of Chemistry and Chemical Engineering, Huaiyin Normal University Huaian 223300 China.
Chem Sci. 2024 Oct 22;15(45):18977-84. doi: 10.1039/d4sc05263c.
Mechanoredox catalysis has emerged as a sustainable approach for organic transformations. Mechanically controlled polymerization that uses mechanoredox catalysts enables synthesis of complex polymers and mechanoresponsive materials with diverse applications. Despite its potential, the focus has predominantly been on free radical polymerization and acrylate monomers. The mechanochemical synthesis of poly(vinyl ether)s (PVEs) poses a significant challenge in the field. Herein, we report an efficient mechanically induced cationic reversible addition-fragmentation chain transfer (mechano-cRAFT) polymerization using 2D MoS as a mechanoredox catalyst, where free radical intermediates can be further oxidized to cations to promote cationic polymerization of vinyl ethers. This mechano-cRAFT polymerization can be conducted in air and with minimal organic solvent, resulting in quantitative monomer conversion. This strategy is applicable to a range of vinyl ether monomers, yielding polymers with controlled molecular weight and narrow dispersity. We also performed trapping experiments to investigate the piezoelectrically mediated redox process, and further validated the mechanism through density functional theory (DFT) calculations.
机械氧化还原催化已成为一种用于有机转化的可持续方法。使用机械氧化还原催化剂的机械控制聚合能够合成具有多种应用的复杂聚合物和机械响应材料。尽管具有潜力，但目前主要关注的是自由基聚合和丙烯酸酯单体。聚（乙烯基醚）（PVE）的机械化学合成在该领域构成了重大挑战。在此，我们报道了一种使用二维MoS作为机械氧化还原催化剂的高效机械诱导阳离子可逆加成-断裂链转移（机械-cRAFT）聚合，其中自由基中间体可进一步氧化为阳离子以促进乙烯基醚的阳离子聚合。这种机械-cRAFT聚合可以在空气中进行，且有机溶剂用量最少，从而实现定量的单体转化。该策略适用于一系列乙烯基醚单体，可得到分子量可控且分散度窄的聚合物。我们还进行了捕获实验以研究压电介导的氧化还原过程，并通过密度泛函理论（DFT）计算进一步验证了该机理。
