A new type of proton exchange membrane (PEM) consisting of polystyrene sulfonic acid (PSSA) latexes, polyvinylidene fluoride (PVDF) and polyvinylpyrrolidone (PVP) has been prepared. The PEM can attain 10(-2) S/cm. of the proton conductivity at room temperature, which is greater than what Nafion(R)-117 offers. An investigation into the morphology and thermal behaviour of the resulting tri-component matrixes has been carried out. The results propose the possibility that PSSA-PVP and PVDF-PVP are the two types of Lewis acid-base pairs existing in the matrixes. The acid-base interactions play a role in facilitating proton transport as well as maintaining dimensional stability of the membrane in hydrated state.