Diverse polymers with chemical recyclability via regioirregular polymerization of a single monomer

The development of polymer products with a circular economy lifecycle represents a path to alleviate the growing plastic waste and energy crisis. However, long-standing challenges include synthesis scalability, tunable material performance and the feasibility of chemical recycling from mixed products. Here we developed a facile regioirregular polymerization strategy to access diverse polymer structures from a single monomer via regioselectivity and dynamic covalent bond exchange. We were able to synthesize polyurethanes (PUx, where x represents the percentage of urethane linkages in the polymer) with tailored urethane contents by modulating the reaction time for the regioirregular polymerization of tetramethylene urethane. The resulting PUx products showcase remarkable composition-dependent material performance, illustrating high strength, toughness and gas barriers comparable with commercial plastics. In particular, PU57 exhibits superior adhesive strength, outperforming commercial glues. Notably, these diverse PUx products could be converted back to a single monomer, representing a proof-of-concept process for a 'single monomer ↔ multiple polymers' closed loop.