Modified silicon carbide whisker reinforced polybenzimidazole used for high temperature proton exchange membrane

Polybenzimidazole containing ether bond (OPBI) was reinforced with silicon carbide whisker (mSiC) modified by 3-aminopropyltriethoxysilane (KH550), and then doped with phosphoric acid (PA) to obtain OPBI/mSiC/PA membranes. These OPBI/mSiC/PA membranes have excellent mechanical strength and oxidative stability and can be used for high temperature proton exchange membrane (HT-PEM). The tensile strength of OPBI/mSiC/PA membranes ranges from 27.3 to 36.8 MPa, and it increases at first and then decreases with the increase of mSiC content. The high mSiC content and PA doping level contribute to improving the proton conductivity of membranes. The proton conductivity of PBI/mSiC-10/PA membrane is 27.1 mS cm−1 at 170 °C without humidity, with an increase of 55.7% compared with that of OPBI/PA membrane. These excellent properties make OPBI/mSiC/PA membranes promising membrane materials for HT-PEM applications.