Copolymerization of Olefins and Conjugated Dienes: A Promising Approach to Produce Recyclable Polyolefins

Creating unsaturated C=C bonds within polyolefin main chains can realize upcycling polyolefins into liquid fuels, telechelic polymers, and even propylene monomer via oxidation and metathesis etc, which provides a sustainable developing route for polyolefins. A few strategies, such as dehydrogenation, sequence bromination and dehydrobromination, have been established, however they inevitably involve an additional synthetic step or problematic reagents. In contrast, incorporation of a C=C bond into the main chain in the manufacturing process is more direct and economical. Copolymerization of olefins and conjugated dienes should be a promising approach, and has been widely investigated. Herein, the development of olefin and conjugated diene copolymerization is summarized into three parts: alternating copolymerization, block copolymerization and cyclocopolymerization. Each part focuses on the catalysts and the corresponding mechanism. The current results suggest that production of the recyclable polyolefin without any performance penalties through copolymerization of olefins with conjugated dienes is still challenging, but point out promising directions.