Highly Sulfonated and Highly Cross-linked Poly(ether ether ketone) Proton Exchange Membranes

摘要

Over the past decade, many efforts have been focused on the development of alternative hydrocarbon polymers to overcome the drawbacks of perfluoropolymers (e.g. Nafion)(l). Among these polymers, sulfonated poly(ether ether ketone) (SPEEK) was shown to be of considerable promise, as it exhibits lower methanol permeability and more less cost than Nafion(2). To prepare SPEEK membranes, different sulfoantion reagents have been used to react with commercial polymers. In these post-sulfonation reactions, the sulfonic acid groups are usually restricted to the activated positions ortho to the aromatic ether bonds, but the precise control of the degree of sulfonation (DS) is difficult, besides the rigorous reaction conditions may lead to the degradation of the polymer backbone or the cross-linking of the polymer chains (3).