L-arabinitol-based functional polyurethanes

Three new polymerizable diols, based on mono-, di-, and tri-O-allyl-L-arabinitol derivatives, were prepared from L-arabinitol as versatile materials for the preparation of tailor-made polyurethanes with varied degrees of functionalization. Their allyl functional groups can take part in thiol-ene reactions, to obtain greatly diverse materials. This “click” reaction with 2-mercaptoethanol was firstly studied on the highly hindered sugar precursor 2,3,4-tri-O-allyl-1,5-di-O-trityl-L-arabinitol, to apply it later to macromolecules. A polyurethane with multiple pendant allyl groups was synthesized by polyaddition reaction of 2,3,4-tri-O-allyl-L-arabinitol with 1,6-hexamethylene diisocyanate, and then functionalized by thiol-ene reaction. The coupling reaction took place in every allyl group, as confirmed by standard techniques. The thermal stability of the novel polyurethanes was investigated by thermogravimetric analysis and differential scanning calorimetry (DSC). This strategy provides a simple and versatile platform for the design of new materials whose functionality can be easily modified.