Isocyanate-Free Routes to Polyurethanes and Poly(hydroxy Urethane)s

Greener routes to polyurethanes are required and arouse a growing interest in the academic and industrial communities. To this purpose, the depletion of fossil resources exacerbates the need of renewable materials. This review details two main routes to phosgene-free and isocyanate-free pathways to polyurethanes: the transurethanization and the cyclic carbonate/amine routes. A focus is also made on bio-based synthons toward non-phosgene and non-isocyanate PUs.