Synthesis and properties of high performance thermoplastic polycarbonate polyurethane elastomers through a non-isocyanate route

Abstract

Thermoplastic polycarbonate polyurethane elastomers (TPCUEs) are synthesized through a solvent-free non-isocyanate melt polycondensation route. The route starts with the synthesis of 1,6-bis(hydroxyethyloxycarbonylamino)hexane (BHCH) from ethylene carbonate and 1,6-hexanediamine, and then the TPCUEs are prepared by the melt polycondensation of BHCH and polycarbonate diols (PCDLs). The TPCUEs are characterized by GPC, FT-IR, ¹H NMR, XRD, AFM, DSC, TGA and tensile testing. The TPCUEs prepared have linear structures and high molecular weights, with Mn over 3.0 × 10⁴ g mol⁻¹. And these TPCUEs exhibit excellent thermal and mechanical properties, with T_g ranging from −18 to −1 °C, T_m ranging from 93 to 122 °C, T_d,5% over 240 °C, tensile strength between 28.1–47.3 Mpa, elongation at break above 1000%, Young's modulus between 13.8–32.7 Mpa and resilience at 200% fixed-length between 70–90%, which makes them a promising alternative to products synthesized through the isocyanate route. In addition, the effects of the hard segment contents and the molecular weights of soft segment on the properties of TPCUEs are researched.