Torsional Strain Enabled Ring‐Opening Polymerization towards Axially Chiral Semiaromatic Polyesters with Chemical Recyclability

Abstract The development of new chemically recyclable polymers via monomer design would provide a transformative strategy to address the energy crisis and plastic pollution problem. Biaryl‐fused cyclic esters were targeted to generate axially chiral polymers, which would impart new material performance. To overcome the non‐polymerizability of the biaryl‐fused monomer DBO, a cyclic ester Me‐DBO installed with dimethyl substitution was prepared to enable its polymerizability via enhancing torsional strain. Impressively, Me‐DBO readily went through well‐controlled ring‐opening polymerization, producing polymer P(Me‐DBO) with high glass transition temperature ( T g >100 °C). Intriguingly, mixing these complementary enantiopure polymers containing axial chirality promoted a transformation from amorphous to crystalline material, affording a semicrystalline stereocomplex with a melting transition temperature more than 300 °C. P(Me‐DBO) were capable of depolymerizing back to Me‐DBO in high efficiency, highlighting an excellent recyclability.