Polyunsaturated Hydrocarbon Polymers via RingOpening Insertion Metathesis Polymerization (ROIMP)

The replacement of persistent plastics with chemically recyclable and environmentally benign alternatives has become an urgent issue for our society. Although an increasing number of degradable polymers are available, many of them are facing with common challenges, that do not always allow for efficient direct replacements for durable plastics such as polyethylene. In this work, we present a new methodology for synthesizing cleavable units containing elastomers and thermoplastics by Ring-Opening Insertion Metathesis Polymerization (ROIMP) of cyclopentene (CP) with unsaturated polyester and polycarbonate oligomers. In the first step, diallyl ester oligomers were synthesized through acyclic diene metathesis (ADMET) polymerization, cyclopentene was then co-polymerized with the oligomers via ROIMP giving longchain polypentenamer (PP) dyads separated by easily cleavable singular ester or carbonate functionalities. Hydrolysis of the formed cleavable PP elastomer resulted in the formation of low molecular weight telechelic, OH-end-functionalized PP oligomers. Hydrogenation of the synthesized elastomers using Wilkinson's catalyst produced saturated long-chain hydrocarbon polymers with randomly distributed, cleavable subunits.