Trehalose-incorporated polymer network by thiol-ene photopolymerization

Abstract

Allyl-etherified trehalose (AxT), with a degree of allylation x=6 or 8, was synthesized by the reaction of α,α-D-trehalose and allyl bromide at a feed molar ratio of 1:1.1x. The degrees of allylation measured by a proton nuclear magnetic resonance (1H-NMR) method for A6T and A8T were 5.99 and 7.51, respectively. Thiol-ene photopolymerizations of AxT with pentaerythritol-based tetrathiol (S4P) and isocyanurate-based trithiol (S3I) produced trehalose-incorporated polymer networks (AxT-S4P and AxT-S3I). All of the photo-cured films exhibited high transparency to visible light. The tan δ peak temperatures of A8T-S4P and A6T-S4P (36.7 °C and 36.8 °C, respectively) were higher than those of A8T-S3I and A6T-S3I (21.9 °C and 23.2 °C, respectively). The former S4P-based film demonstrated much higher tensile strength and modulus at room temperature than the latter S3I-based film did. The 5% weight loss temperature of the A8T-based film was higher than that of the A6T-based film.