Super Anti‐Water Permeability and High Toughness of CO₂‐Derived Polycarbonate Polyurethane via Copolymerization with Polydimethylsiloxane

Abstract Polycarbonate thermoplastic polyurethanes (TPUs) have gained popularity for their excellent mechanical properties and relatively good environmental tolerance. However, traditional petroleum‐based TPUs are heavily dependent on non‐renewable resources and difficult to balance anti‐water permeability with flexibility, severely limiting their application in hostile situations. In this article, the newly designed TPUs are synthesized with CO 2 ‐derived oligomeric polycarbonate diol (PPCDL, with a carbonate content >90%) and polydimethylsiloxane (PDMS) as the core materials. The influences of PDMS on the structures, as well as the properties of thermal, optical, mechanical, and anti‐water permeability of TPUs are thoroughly investigated. The results have shown that the strategy is successful in improving the performance of TPUs with both super anti‐water permeability and high toughness simultaneously. The introduction of PDMS significantly improves the toughness (up to 100.8 MJ m −3 ) and elongation (at break>800%) of the materials while maintaining moderate tensile strength (15–28 MPa). More importantly, the hydrophobic nature of PDMS further enhances the anti‐water permeability (water vapor transfer rate as low as 0.10 g m −2 day −1 ). This work proposes a novel strategy for developing eco‐friendly TPUs with excellent overall performances of high toughness, tunable mechanical strength, and environmental resilience, demonstrating potential wide applications requiring high durability and moisture resistance.