AbstractCovalently crosslinked polymeric materials, known as thermosets, possess enhanced mechanical strength and thermal stability relative to the corresponding uncrosslinked thermoplastics. However, the presence of covalent inter‐chain crosslinks that makes thermosets so attractive is precisely what makes them so difficult to reprocess and recycle. Here, we demonstrate the introduction of chemically cleavable groups into a bis‐diazirine crosslinker. Application of this cleavable crosslinker reagent to commercial low‐functionality polyolefins (or to a small‐molecule model) results in the rapid, efficient introduction of molecular crosslinks that can be uncoupled by specific chemical inputs. These proof‐of‐concept findings provide one potential strategy for circularization of the thermoplastic/thermoset plastics economy, and may allow crosslinked polyolefins to be manufactured, used, reprocessed, and re‐used without losing value. As an added benefit, the method allows the ready introduction of functionality into non‐functionalized commodity polymers.
摘要共价交联聚合物材料,即热固性材料,与相应的非交联热塑性塑料相比,具有更高的机械强度和热稳定性。然而,共价链间交联的存在使热固性塑料具有如此大的吸引力,也正是这种存在使热固性塑料难以再加工和回收利用。在此,我们展示了在双氮丙啶交联剂中引入化学可裂解基团的方法。将这种可裂解交联剂试剂应用于商用低官能度聚烯烃(或小分子模型),可快速、高效地引入分子交联,通过特定的化学输入即可解除交联。这些概念验证结果为热塑性塑料/热固性塑料经济的循环利用提供了一种潜在策略,可使交联聚烯烃在不损失价值的情况下进行生产、使用、再加工和再利用。该方法的另一个好处是,可随时将功能性引入非功能化商品聚合物。