(509cw) Development of sustainable polyurethanes and polyesters from biomass-derived diols by aldol-condensation and controlled hydrogenation

Sustainable polyurethanes and polyesters were produced from a diol that was synthesized by aldol-condensation of biomass-derived 5-hydroxymethyl furfural (HMF) and acetone, named HAH. HAH was selectively hydrogenated over Cu and Ru catalysts to produce partially-hydrogenated (PHAH) and fully-hydrogenated (FHAH) in high yield (≥91 mol%), respectively. The degree of HAH hydrogenation resulted in series of diols that can give unique properties to polymers by being incorporated to the polymer structure. For example, HAH units in these polymers have UV absorbing ability and improve the thermal stability and stiffness of the polymers, compared to ethylene glycol-based polyurethanes. Polyurethanes, comprising PHAH units, provide electron-rich furan functional groups to append maleimide compounds by Diels–Alder reactions. Maleimide compounds, such as bismaleimide, can be used to produce reversible crosslinking of the polymers or to impart functionality to PHAH (giving rise to anti-microbial activity or controlled drug delivery). The symmetric triol structure of FHAH leads to energy-dissipating rubbers with branched structures. The polyester produced from HAH could be used in packaging applications. As a result, biomass-derived HAH, PHAH, and FHAH become functional diols for the production of performance-advantaged polymers with UV absorption properties, binding sites for Diels–Alder reactions, and crosslinking ability. The biomass-derived diols can be blended with each other or with petroleum-based diols (e.g., ethylene glycol) to further tune the properties.