A Multiply and Long-Chain Branched Polyolefin with Low Density Polyethylene (LDPE)-Like Properties Containing Two Types of Functional Groups.

Low-density polyethylene (LDPE) is an important material or plastic, which, unfortunately, is synthesized under very harsh conditions and challenging to recycle. We report here on a highly flexible catalytic synthesis of multiply branched and long-chain branched polyolefins under mild conditions. We combine coordinative chain transfer polymerization of ethylene and branched alpha-olefins with ring-opening metathesis polymerization and hydrogenation catalysis. Our plastic contains two types of functional groups: olefins and esters. The olefin functional groups can be used to enable closed-loop recycling, and the ester groups permit faster decomposition than LDPE to potentially reduce the micro-plastic formation or enable a second depolymerization pathway. Our material matches key properties of LDPE, such as the melting point, rheology and stress-strain behavior.