Progress in non-isocyanate polyurethanes synthesized from cyclic carbonate intermediates and di- or polyamines in the context of structure–properties relationship and from an environmental point of view

Commercially, polyurethanes are produced by the reaction of diisocyanates, polyols (polyester or polyether) and low molecular weight chain extender. Toxicity, moisture sensitivity and phosgene-based synthesis of diisocyanates resulted in investigations focused on obtaining the non-isocyanate polyurethanes (NIPUs). This work presents the review of synthesis and structure–properties relationship of non-isocyanate polyurethanes obtained by reacting cyclic carbonated intermediates with diamines or polyamines. Moreover, the presented methods of NIPU synthesis were analysed from the environmental point of view. Described five-membered ring cyclic carbonate intermediates were obtained by carbonation of glycidyl ethers or thiol-ene coupling of unsaturated cyclic carbonate monomers and thiols. The special interest was put on the bio-based non-isocyanate polyurethanes, obtained from chemically modified bio-based substances, e.g. carbonated vegetable oils. The mechanical and thermal properties of NIPUs are affected by functionality, structure and molecular weight of cyclic carbonate intermediates and diamines or polyamines.