Closed‐loop recycling of <scp>N</scp>ylon‐6 to <scp>C</scp>aprolactam catalyzed by a green and effective phosphazene base

Abstract Chemical recycling of polymers to initial monomers (CRM) has emerged as an advanced solution for waste plastic management. In particular, developing promising catalytic methods are a crucial issue. In this work, focusing on the closed‐loop recycling of Nylon‐6 (PA6) to caprolactam (CPL), a phosphazene base t ‐BuP 4 is exploited as a green organocatalyst. The versatility of this catalytic system is confirmed by the calculation of activation energy, as well as the effective and selective depolymerization process. Meanwhile, the catalyst also displays good recyclability and scalability. Experimental kinetic data reveal that the depolymerization mechanism involved random chain scission after the interaction of catalyst and amide. This work provides a useful strategy for the treatment of post‐consumer waste PA6.