Renewable carvone-based polyols for use in polyurethane thermosets

A series of carvone-derived statistical copolymers, CMXD (CM = carvomenthide; X = %D; D = dihydrocarvide), were prepared by ring-opening polymerization. The olefinic side chains were subsequently modified by the thiol-ene reaction using mercaptoethanol to provide CMXD′ (D′ = hydroxy-functionalized dihydrocarvide unit). The resulting samples, having hydroxy functionality dictated by the original monomer feed ratio, were exploited as renewable polyols in the synthesis of polyurethanes. The polyurethane films were characterized by tensile testing, differential scanning calorimetry and dynamic mechanical analysis. Polyols with 4-5 hydroxyls per chain produced mechanically robust thermoplastic polyurethanes.