Synthesis and properties of biobased non-isocyanate aliphatic thermoplastic polyurethane elastomers with butanediurethane hard segments

A simple non-isocyanate route is established to synthesize biobased aliphatic thermoplastic polyurethane elastomers (TPEUs) with excellent mechanical properties. Melt transurethane co-polycondensation of bis(hydroxyethyl) butanediurethane (BHBDU) with different polycaprolactone-diols (PCDLs) was conducted at 170°C under a reduced pressure of 3 mmHg, and a series of TPEUs were prepared. The TPEUs were characterized by gel permeation chromatography, FT-IR, 1H-NMR, wide angle X-ray scattering, DSC, TGA, dynamic mechanical analysis, atomic force microscopy, and tensile test. TPUEs exhibited Mn above 25,000 g/mol, Tg of −36 to 1°C, Tm up to 105°C, maximal tensile strength of 38 MPa with a strain at break of 926%, and resilience of 80%–90%. BHBDU and PCDLs may be synthesized from bioresources. Biobased aliphatic TPU elastomers with excellent tensile strength and resilience were prepared successfully through a non-isocyanate route.