Synthesis and characterization of new ion conductors based on butadiene styrene copolymers

In this work, we report the synthesis, kinetic study and microstructure characterization of a new proton conductor based on sulfonated polybutadiene–styrene copolymer (HPBS). Block copolymer ionomers were prepared through sulfonation of part of the styrene units. The free acid (HPBS-SH) sample was characterized using FT-IR spectroscopy and X-ray Photoelectron Spectroscopy (XPS) to confirm and quantify sulfonation. Microstructural characterization of the samples was carried out using Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), and Impedance Spectroscopy (IS). DMA and DSC analysis have shown that Tg (HPB) remains constant for all the samples studied, while glass transition temperature of polystyrene (PS) measured present an increase about 30 °C after sulfonation. Complex impedance measurements have shown that proton conductivity of HPBS-SH membrane was about 10−3–10−2 S cm−1, lower values were observed generally in the case of blends.