Novel boron-containing triazole functional copolymers as anhydrous proton conductive membranes

In the present work, the synthesis, thermal and proton conducting properties of copolymers based on 4-vinylbenzeneboronic acid (VBBA) and 1-vinyl-1,2,4-triazole (VTri) were investigated. The copolymers were produced by free-radical copolymerization of the corresponding monomers at several monomer feed compositions to obtain copolymers which were abbreviated as P(VBBA-co-VTri). The copolymer samples were doped with H₃PO₄ at several stoichiometric ratios to obtain proton conductive copolymer electrolytes. The composition of the copolymers was also determined by elemental analysis. The structure of the copolymer and the electrolytes were studied by FT-IR spectroscopy. The thermal properties were investigated by TGA which confirmed that the materials are stable up to at least 150 °C. In the absence of humidity, the copolymer electrolyte, P(VBBA-co-VTri)1:2 X = 3 has a proton conductivity of 6 × 10⁻³ S/cm at 120 °C. Cyclic voltammetry results demonstrated that the stability window of P(VBBA-co-VTri) is 4 V.