Photo crosslinked stilbene-containing sulfonated polyimide membranes as proton exchange membranes in fuel cell

Stilbene containing sulfonated polyimide membranes were synthesized from 1, 4, 5, 8-naphthalenetetracarboxylic dianhydride, 2-bis (4-aminophenoxy) phenyl) hexafluoropropane, 2, 2′-benzidinedisulfonic acid and 4,4′-diamino stilbene. Subsequently, they were photo crosslinked and characterized to investigate their suitability for fuel cell applications. The synthesized membranes exhibit water uptake of 24.47–29.78%, proton conductivity of 0.016–0.046 S cm−1 at 30 °C, and the ion exchange capacity of 1.450–1.485 mequiv g−1. The fuel cell performance of stilbene containing sulfonated polyimide membrane showed a power density of 0.24 W/cm2. The hydrolytic stability of uncrosslinked stilbene containing sulfonated polyimide membranes was 47–68 h, but, after the photocrosslinking, it was increased up to 109 h. The uncrosslinked membranes showed tensile strength in the range of 36.74–47.38 MPa, and after photocrosslinking, the tensile strength was increased in the range of 42.34–54.71 MPa. The oxidative stability of uncrosslinked membranes was found to be in the range of 45–48 h whereas the photocrosslinked membranes showed oxidative stability in the range of 51–57 h.