Synthesis of non-isocyanate polyurethanes with high-performance and self-healing properties

Due to the utilization of the potentially hazardous monomer, isocyanate compound, polyurethanes (PUs) with good properties are restricted in several fields, such as bio-engineering. Non-isocyanate polyurethanes (NIPUs) with high overall performance and self-healing properties were synthesized by dicarbamate, bio-based isosorbide (IS) and polycarbonate diols (PCDLs) through a solvent-free and ecologically friendly melt polycondensation route. Previously, few bio-based monomers have been introduced into polycondensation reactions of PUs. Chemical structures of NIPUs were analyzed by Fourier transform-infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (H-1 NMR) and gel permeation chromatography (GPC). With changing the IS content and the molecular weight of PCDL, the obtained NIPUs had linear structures and high molecular weights ranging from 3.3 x 10(4) to 5.9 x 10(4) g/mol. Results of tensile testing, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) suggested NIPUs had well thermal and mechanical properties, with T-d,T-5% above 286.2 degrees C and tensile strength between 8.0 and 16.7 MPa due to the crystallization and the hydrogen bonding interactions. Furthermore, the NIPUs exhibited self-healing ability and recyclability, having great potential for industrialization.