Sulfonated Commercial High Impact Polystyrene as a Solid Polyelectrolyte for Fuel Cells

ABSTRACT Sulfonated high‐impact polystyrene (SHIPS) membranes with different polybutadiene content and morphologies were prepared and evaluated as proton exchange membranes (PEMs) for hydrogen fuel cells. Sulfonation was confirmed by FTIR, GPC, and TGA through the appearance of vibrational bands related to the SO 3 H functional group, an increase in molecular weight, and a thermal weight loss around 150°C associated with ionic group decomposition. Vitreous transitions (Tg) were slightly affected by the ionic interactions. TEM and TMA analyses showed that SHIPS retained its original grafted particle morphology and preserved, in general, the flexural modulus of the original HIPS. The membrane exhibited ion exchange capacity (IEC) of 0.25–0.85 meq/g, water uptake (WU) below (< 20%) and proton conductivity ( σ ) of 10 −4 to 10 −3 S/cm. Notably, the presence of the rubber phase did not compromise proton transport. These findings demonstrate the promising potential of SHIPS as high‐performance PEMs for hydrogen fuel cell applications.