Polycarbonate Vitrimers and Dynamic Co-Networks From Epoxide/Carbon Dioxide Copolymerization.

Understanding how backbone chemistry and crosslinker functionality shape vitrimer behavior is key to designing recyclable networks with predictable performance. In this work, we use CO2-derived poly(propylene carbonate) (PPC) and poly(cyclohexene carbonate) (PCHC) backbones to systematically probe how molecular structure influences glass transition, stress-relaxation dynamics and mechanical properties in β-hydroxyester vitrimers. By varying epoxide identity and backbone composition, we access a broad thermomechanical performance window, including tunable Tg values (-2 to 73°C) and materials with mechanical behaviors ranging from those of highly extensible networks (>200% elongation at break) to those of stiff, glassy materials with Young's moduli of 1.8 GPa and tensile strengths up to 34.5 MPa. Blending PPC and PCHC during formation of dynamic networks further reveals miscibility boundaries and nanoscale morphologies that correlate with thermal and dynamic behaviors. Together, these results establish practical structure-property guidelines for designing CO2-based polycarbonate vitrimers with tunable behavior.