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

Abstract 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.