Xylose- and Nucleoside-Based Polymers via Thiol–ene Polymerization toward Sugar-Derived Solid Polymer Electrolytes

A series of copolymers have been prepared via thiol–ene polymerization of bioderived α,ω-unsaturated diene monomers with dithiols toward application as solid polymer electrolytes (SPEs) for Li⁺-ion conduction. Amorphous polyesters and polyethers with low T_g’s (−31 to −11 °C) were first prepared from xylose-based monomers (with varying lengths of fatty acid moiety) and 2,2′-(ethylenedioxy)diethanethiol (EDT). Cross-linking by incorporation of a trifunctional monomer also produced a series of SPEs with ionic conductivities up to 2.2 × 10^–5 S cm^–1 at 60 °C and electrochemical stability up to 5.08 V, a significant improvement over previous xylose-derived materials. Furthermore, a series of copolymers bearing nucleoside moieties were prepared to exploit the complementary base-pairing interaction of nucleobases. Flexible, transparent, and reprocessable SPE films were thus prepared with improved ionic conductivity (up to 1.5 × 10^–4 S cm^–1 at 60 °C), hydrolytic degradability, and potential self-healing capabilities.