Functionalized Polysulfones: Methods for Chemical Modification and Membrane Applications

Sulfonated hydrocarbon membranes for medium-temperature and low-humidity proton exchange membrane fuel cells (PEMFCs)

“…This phase separated morphology can decelerate polymer main chain degradation by radical species that are present in the water channel [38]. In previous research by the Jannasch group, a sulfophenyl ring was introduced to polysulfone using the above lithiation process developed by Guiver et al [65], followed by subsequent anionic reaction with sulfobenzoic acid cyclic anhydride, as shown in Fig. 8 [66].…”

“…In a conventional sulfonation reaction, sulfonic acid groups are introduced onto the ortho-position of electron-rich benzene rings activated by electron-donating groups such as ether linkages, which can give rise to instability due to the low reaction energy barrier [63]. However, sulfonic acid groups introduced by lithiation are potentially more stable and exhibit a higher acidity because lithiation occurs on electron-poor benzene rings that are deactivated by the electron-withdrawing group such as a sulfone group [34,64,65]. Despite this potential advantage, the final oxidation step that follows lithiation and sulfination can result in a reduction in the expected IEC, and chain degradation [62].…”

Phenyltrimethylammonium Functionalized Polysulfone Anion Exchange Membranes

“…1,2 The introduction of functional groups into PSf extends the range of potential applications of these high-performance materials with specific function and wider scope. The introduction of functionality into PSf has been accomplished by copolymerization with functionalized comonomers or by postfunctionalization of commercially available polymers.…”

“…Examples of the functionalization chemistry include sulfonation, 3 bromination, 4 chloromethylation, 5 amidoalkylation, 6 and lithiation. 7−9 Functionalized PSfs have been actively investigated as membrane materials for gas 1,2,10,11 and liquid separation 12 and for fuel cells (FCs). 13−16 For example, sulfonated polysulfones, which have been synthesized by copolymerization with a sulfonated comonomer or by postsulfonation, 13,16 have been widely studied for proton exchange membranes (PEMs) for acidic fuel cells to provide alternatives to established Nafion that has dominated the field.…”

A Novel Bisphenol Monomer with Grafting Capability and the Resulting Poly(arylene ether sulfone)s

“…One postpolymerization method is to first react polysulfone with butyllithium and then react the lithiated polysulfone with 4-fluorobenzoyl chloride to introduce 4-fluorobenzoyl side chains to polymer main chain. 3,4 However, while this method is convenient, it requires stringent reaction conditions. Recently, a divergent approach with an activation/condensation sequence was developed.…”