Synthesis and characterization of advanced biobased thermoplastic nonisocyanate polyurethanes, with controlled aromatic-aliphatic architectures

Abstract

The aim of this study was the elaboration of thermoplastic and biobased nonisocyanate polyurethanes (TNIPUs) based on different aromatic-aliphatic architectures. A rigid aromatic bis(cyclic carbonate) was synthesized from terephthalic acid, and subsequently used with various diamines for the preparation of TNIPUs. A two-step method was investigated to design advanced macromolecular architectures. All TNIPUs and corresponding intermediates were fully characterized. The influence of various parameters such as the ratio between the constituting building blocks and the chemical structure on NIPU properties was studied. Thermal and mechanical results show that the TNIPUs presenting the highest molar masses and the highest properties were synthesized from dimer diamine prepolymers. A high content of terephthalic acid and short-chain diamine increases the glass transition temperature and leads to good performances, with a balance between elongation and tensile strength properties. The final TNIPUs present biobased content up to 76%.