Incorporating Carbamate Groups into Polyolefin Elastomers for High Performance and Closed-Loop Recyclability

Polar polyolefins find widespread applications owing to their superior properties. Conventional synthesis methods incorporated polar groups into the side chains of polyolefins, offering effective pathways for diverse functional applications. In contrast, reports on main-chain polar polyolefins remain relatively scarce, and systematic studies of their properties are particularly underdeveloped. Here, we report a hydrogen-bonding-enhanced main-chain polar polyolefin (H-PO) synthesized via efficient polymerization of α,ω-dihydroxy telechelic polyolefins (tPO) and hexamethylene diisocyanate (HDI), incorporating 3.6-10.6 carbamate linkages per 1000C into the polyolefin backbone. The resulting H-PO shows high molecular weight (M_n up to 120.6 kDa), excellent strength, elongation (up to 3048%), and toughness (up to 268 MJ·m^-3). Notably, manganese-catalyzed hydrogenolysis allows closed-loop recycling of tPO macromonomers and HDI precursors (≥95% yield). This approach uniquely combines high performance and easy synthesis of high-molecular-weight polyolefins with efficient circularity within a single material through main-chain polar linkages. It offers a new way to design high-performance, sustainable olefin polymer materials by utilizing multifunctional linkages for closed-loop recycling and enhanced properties.