Preparation and Characterization of Proton Exchange Composite Membranes Pore-Filled with ZrP/Sulfonated Polybenzimidazole
SPBI-ZrP/ePTFE proton exchange composite membranes were prepared by pore-filling techniques.
Using ePTFE porous substrate (supporting material) filled with SPBI-ZrP polymer electrolytes.
The microstructure and performance of the membranes were characterized by FESEM, FT-IR, dry-wet weighting method, tensile test and AC impedance.
The results indicate that SPBI-ZrP is successfully filled into the ePTFE substrate and the membrane surface is smooth.
The swelling degree of the SPBI-ZrP-2.5 membrane in thickness direction is about 7.3 times of that of the SPBI-ZrP-2.5/ePTFE membrane, because ePTFE can effectively suppress membrane swelling and improve membrane dimensional stability. Simultaneously, because of the reinforced effect of ePTFE, the mechanical strength of the SPBI-ZrP-2.5/ePTFE membrane is 19.86% higher than that of SPBI-ZrP-2.5.
The SPBI-ZrP-2.5/ePTFE membrane shows a high proton conductivity of 0.222 and 0.071 S·cm--1 at 160℃ and 80℃ under 100% relative humidity, respectively. The proton conductivity of Nafion membrane (EW=1100) is 0.077 S·cm-1 at 80℃ and decreases sharply when temperature exceeds 100℃.
These results indicate that SPBI-ZrP/ePTFE membranes have good proton conductivity at higher temperature, which can be applied in fuel cells with high temperature proton exchange membranes.
Results and Discussion