Zhang Xiaohui, Zhao Yajun, Chen Meng, Ji Minghang, Sha Ye, Nozaki Kyoko, Tang Shan
Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China.
Department of Chemistry and Material Science, College of Science, Nanjing Forestry University, Nanjing 210037, China.
J Am Chem Soc. 2024 Aug 28;146(34):24024-24032. doi: 10.1021/jacs.4c07445. Epub 2024 Aug 17.
Polyolefins are recognized as fundamental plastic materials that are manufactured in the largest quantities among all synthetic polymers. The chemical inertness of the saturated hydrocarbon chains is crucial for storing and using polyolefin plastics, but poses significant environmental challenges related to plastic pollution. Here, we report a versatile approach to creating polyethylene materials with tunable degradability by incorporating in-chain mechanophores. Through palladium-catalyzed coordination/insertion copolymerization of ethylene with cyclobutene-fused comonomers, several cyclobutane-fused mechanophores were successfully incorporated with varied insertion ratios (0.35-26 mol %). The resulting polyethylene materials with in-chain mechanophores exhibit both high thermal stability and remarkable acid resistance. Upon mechanochemical activation by ultrasonication or ball-milling, degradable functional units (imide and ester groups) are introduced into the main polymer chain. The synergy of mechanochemical activation and acid hydrolysis facilitates the efficient degradation of high molecular weight polyethylene materials into telechelic oligomers.
聚烯烃被公认为是基础塑料材料，在所有合成聚合物中产量最大。饱和烃链的化学惰性对于聚烯烃塑料的储存和使用至关重要，但也带来了与塑料污染相关的重大环境挑战。在此，我们报道了一种通用方法，通过引入链内机械响应基团来制备具有可调降解性的聚乙烯材料。通过乙烯与环丁烯稠合共聚单体的钯催化配位/插入共聚反应，成功地以不同的插入比例（0.35 - 26摩尔%）引入了几种环丁烷稠合的机械响应基团。所得具有链内机械响应基团的聚乙烯材料兼具高热稳定性和显著的耐酸性。在通过超声或球磨进行机械化学活化后，可降解功能单元（酰亚胺和酯基）被引入到主聚合物链中。机械化学活化和酸水解的协同作用促进了高分子量聚乙烯材料高效降解为遥爪低聚物。
