Biobased, High-Performance Fully Alicyclic Copolycarbonates

To advance the development of sustainable high-performance polycarbonates, a series of novel copolycarbonates (PITCs) were designed and synthesized using two biobased alicyclic building blocks: isosorbide (IS) and 2,5-tetrahydrofurandimethanol (THFDM). The target polycarbonates were prepared via melt polymerization, yielding materials with number-average molecular weights ranging from 51,600 to 75,500 g/mol. By integrating density functional theory calculations with kinetic studies, we elucidated the reaction mechanism and monomer reactivity, confirming that intermolecular interactions between the building blocks promote polymerization efficiency. Notably, the incorporation of THFDM significantly enhanced the cohesive energy density of the PITC matrix, enabling PI89T11C and PI70T30C to achieve balanced performance: high glass transition temperatures (Tg) of 151.2 °C and 115.8 °C, respectively, superior tensile strength (74–75 MPa), and excellent elongation at break (70–92%). In contrast, PITCs with high THFDM content (≥90 mol %) exhibited exceptional flexibility, with elongation at break values ranging from 900% to 1600%. Additionally, all PITCs maintained high transparency (∼93% light transmittance) and elevated biobased content (82–84%). These biobased, high-performance copolycarbonates thus hold significant promise for the development of eco-friendly and sustainable advanced engineering materials.