Synthesis and conductivity of hyperbranched poly(triazolium)s with various end-capping groups

Abstract

A series of novel hyperbranched poly(triazolium)s with different terminal groups were synthesized by alkylation and anion exchange reactions of the corresponding hyperbranched poly(triazole)s, which were obtained from an AB₂-type monomer via Cu(I)-catalyzed azide–alkyne cycloaddition polymerization. The hyperbranched poly(triazolium)s showed high thermal stability with decomposition temperatures of 328–361 °C, and good flexibility, with glass transition temperatures (T_g) ranging from −6.2 to −14.9 °C. Among them, an oligo(ethylene glycol)-terminated hyperbranched poly(triazolium) presented the lowest T_g of −14.9 °C, the highest ionic conductivity (7.70 × 10⁻⁶ S cm⁻¹ at 30 °C and 1.02 × 10⁻³ S cm⁻¹ at 110 °C) and a wide electrochemical stability window of 6.0 V. Therefore, these hyperbranched poly(triazolium)s could act as new electrolyte materials.