Recyclable Polypentenamers with Precise Crystallization and Versatile Functionalization

Abstract

The recyclability and reuse of polymeric materials have become increasingly necessary. Introducing depolymerizability or degradability into polymers without compromising the mechanical performance but concurrently endowing the polymers with new properties is challenging. In this contribution, a family of polypentenamers with different alkyl side chains ranging from nonyl to octacosyl were synthesized. The polycyclopentene backbone provides polymer depolymerizability, promoting degradation into their original building blocks, which also can repolymerize into polymers, realizing full closed-loop recycling. Crystalline side chains help afford polyethylene-like strength and modulus. The lamellar thickness of sub-5 nm can be precisely controlled. Inserting an ethylene glycol unit along the side chain allowed them to be easily transferred into 10 kinds of new polyolefins with various functions. These degradable polycyclopentene-backboned polymers with crystalline pendants pave sustainable ways for the recyclability and reuse of polyolefin materials for, for example, packaging applications.