Lipidic polyols using thiol-ene/yne strategy for crosslinked polyurethanes

Oleic acid and diacid were converted into propargylic esters followed by thiol-ene/yne coupling (TEC/TYC) functionalization in presence of mercaptoethanol. The multi-radical addition on fatty esters leads to the formation of lipidic polyols (OH1 and OH2), as judged by 1H NMR and mass spectroscopies as well as by steric exclusion chromatography (SEC). The crosslinking reaction between TEC/TYC-based polyols and MDI isocyanate reactant was monitored by FTIR experiment and reaction parameters were optimized. By differential scanning calorimetry (DSC), relatively high glass transitions are measured corresponding to structure with little or without dangling chain. Moreover, the thermal stability of the resulting plant oil-based polyurethane materials (PU1 and PU2) were found to be fully consistent with that of other lipidic polyurethanes respecting a three-step process. Thanks to TYC methodology, fatty diacid produces lipidic polyol without dangling chain and lipidic thermoset PU with relatively high Tg.