Synthesis and degradation of an erythritol- and cystine-derived polyhydroxyurethane containing cleavable disulfide bonds

Abstract

A biomass-based polyhydroxyurethane (PHU) containing disulfide bonds in the main chain was synthesized from a sugar-derived bifunctional cyclic carbonate and dimethyl ʟ-cystinate. Dynamic light scattering measurements revealed that PHU formed aggregates with hydrodynamic diameters (Dh) of approximately 120–130 nm in MeOH and tetrahydrofuran (THF), while unimolecularly existed in DMF (Dh ≤ 3 nm). PHU decomposed by the addition of 1,4-dithiothreitol as a reducing agent, which was confirmed by size exclusion chromatography. PHU decomposed faster in DMF than in MeOH and THF, probably due to the lack of aggregation in DMF and the high polarity of DMF.