Synthesis and properties of bio-based polyurethanes bearing hydroxy groups derived from alditols

Abstract

Four kinds of bio-based polyurethanes bearing hydroxy groups in the pendants were synthesized by the polyaddition of D-mannitol- and D,L-erythritol-derived diols (1,2:5,6-di-O-isopropylidene-D-mannitol and 1,2-O-isopropylidene-D,L-erythritol) with hexamethylene diisocyanate and methyl (S)-2,6-diisocyanatohexanoate and the subsequent deprotection of the isopropylidene groups. They were hydrolyzed much more quickly than the corresponding protected polyurethanes at 50 °C and pH 7.0, although their hydrolytic degradation rate was lower than that of polyurethanes with saccharic and glucuronic lactone groups, which had been reported in our previous articles. The introduction of D-mannitol units to the polyether-polyurethanes containing poly(oxytetramethylene) glycol units also enhanced their hydrolyzibility. © 2010 Wiley Periodicals, Inc.