Fabrication and Characteristics of Poly(benzimidazole/fluoro/ether/siloxane/amide)/Sulfonated Polystyrene/Silica Nanoparticle-Based Proton Exchange Membranes Doped With Phosphoric Acid

Abstract Novel poly(benzimidazole/fluoro/ether/siloxane/amide) (PBFESA) was developed for the formation of hybrid proton exchange membrane. Afterward, phosphoric acid doped PBFESA/PS-S/SiNPs was prepared with PBFESA, sulfonated polystyrene (PS-S), and 0.1–2 wt% silica nanoparticles (SiNPs). Tensile strength of acid doped PBFESA/PS-S/SiNPs nanocomposites increased from 63.9 to 68.1 MPa with increasing SiNPs loading. They had higher ion exchange capacity (IEC) of 2.3–3.3 mmol/g and proton conductivity of 1.9–2.7 S/cm at 80°C (higher than perfluorinated Nafion 117 membrane 1.1 × 10−1 S/cm). A H2/O2 fuel cell using PBFESA/PS-S/SiNPs 2 (IEC 3.3 mmol/g) showed better performance than Nafion 117 at 40°C (30% RH). Keywords: Nafion 117poly(benzimidazole/fluoro/ether/siloxane/amide)proton conductivitysilica nanoparticlessulfonated polystyrene Notes 1Toughness was determined by integrating the area under the stress-strain curve. 2The number in the sample designation refers to wt% of nanopartricle in the sample. a Measured at 80°C. b Measured in water. c Nafion 117 membrane was tested under the same conditions as with other samples. Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/gpom.