Polyethylene Incorporating Diels-Alder Comonomers: A "Trojan Horse" Strategy for Chemically Recyclable Polyolefins.

Polyolefins with periodic unsaturation in the backbone chain are sought after for synthesizing chemically recyclable polymers or telechelic polyolefin macromonomers. Here we introduce a bottom-up synthesis of unsaturated high-density polyethylene (HDPE) via copolymerization of ethylene with dimethyl 7-oxabicyclo[2.2.1]hepta-2,5-diene-3,5-dicarboxylate followed by post-polymerization retro-Diels-Alder to unveil hidden double bonds in the polymer backbone. The incorporation of this "Trojan Horse" comonomer was varied and a series of unsaturated HDPE polymers with block lengths of 1.2, 1.9, and 3.5 kDa between double bonds was synthesized. Cross metathesis of unsaturated HDPE samples with 2-hydroxyethyl acrylate yielded telechelic ester terminated PE macromonomers suitable for the preparation of ester-linked PE. These materials were depolymerized and repolymerized, making them suitable candidates for chemical recycling. The ester-linked PE displayed thermal and mechanical properties comparable to commercial HDPE.

Parke SM ，Lopez JC ，Cui S ，LaPointe AM ，Coates GW ... -  《-》

Chemically Recyclable Linear and Branched Polyethylenes Synthesized from Stoichiometrically Self-Balanced Telechelic Polyethylenes.

Jang YJ ，Nguyen S ，Hillmyer MA 《-》

Catalytic Chemical Recycling of Post-Consumer Polyethylene.

Arroyave A ，Cui S ，Lopez JC ，Kocen AL ，LaPointe AM ，Delferro M ，Coates GW ... -  《-》

Chemically Recyclable Ester-Linked Polypropylene.

Kocen AL ，Cui S ，Lin TW ，LaPointe AM ，Coates GW ... -  《-》

Thermally Robust yet Deconstructable and Chemically Recyclable High-Density Polyethylene (HDPE)-Like Materials Based on Si-O Bonds.

Johnson AM ，Johnson JA 《-》