Résumé
Hydrocarbon‐based polymer electrolytes hold great promise for practical electrochemical device deployment but suffer from limitations such as ionic conductivity, alkaline stability, and hydrophobicity. This work reports a new membrane, LLDPE‐g‐1VIm/4VP, prepared by radiation grafting a binary mixture of 1‐vinyl imidazole and 4‐vinylpyridine onto linear low‐density polyethylene. Short branches in LLDPE are hypothesized to regulate water uptake, thus improving dimensional stability. Under optimized conditions, the membrane exhibits a relatively high ionic conductivity of 39.86 mS cm −1 at 70 °C, good mechanical strength, improved dimensional stability, and moderate alkaline stability even after 240 h at 60 °C under harsh conditions. Preliminary evaluations demonstrate their potential as solid polymer electrolytes for electrochemical energy applications, including alkaline anion exchange membrane fuel cells.