PEM, POSS, nanocomposite, high temperature
In this study, two methods, direct mixing polyhedral oligomeric silsesquioxanos (POSS) with poly(2,5-benzimidazole) (ABPBI) and in-situ synthesis were employed to prepare ABPBI based composite membrane materials, respectively. The morphologies of pristine and composite membranes were characterised by optical microscopy and scanning electron microscopy; the thermal stabilities were measured by Thermogravimetric analysis; the pristine and modified polymers’ structures were characterised by Fourier transform infrared spectroscopy, elemental analysis and X-ray diffraction. The water uptake, acid doping level and proton conductivity were investigated. Experimental results showed that, the POSS particles dispersed uniformly in ABPBI polymer with nano-size; the water uptake and proton conductivity of composite membranes were improved over 10% and 50% compared with that of pristine membranes respectively. The composite membranes showed much improved proton conductivity at high temperatures (over 100°C) and to 0.01S/cm was comparable with commercial Nafion 117 membranes at room temperature and ambient atmosphere, which indicated that the POSS hybrid ABPBI composite membranes could be used for both high and low temperature fuel cell applications.