Synthesis and photocrosslinking of disulfonated poly(arylene ether sulfone) copolymers for potential reverse osmosis membrane materials

Disulfonated poly(arylene ether sulfone) random copolymers with controlled oligomeric molecular weights were synthesized via nucleophilic aromatic substitution step polymerization. A monofunctional endcapping reagent, meta-aminophenol, was utilized to control the molecular weight of the oligomers and to install telechelic amine endgroups. The meta-aminophenol end-capped oligomers were reacted with acryloyl chloride to obtain novel crosslinkable poly(arylene ether sulfone) oligomers with acrylamide groups on both ends. The chemical compositions of the functional oligomers were characterized by H-1 NMR spectroscopy to determine the degree of sulfonation and concentrations of acrylamide endgroups. The acrylamide-terminated oligomers were crosslinked with UV radiation in the presence of a multifunctional acrylate and a UV photoinitiator. Transparent, free-standing, dense films were obtained with high gel fractions. FTIR spectroscopy was utilized to observe the progress of the photo-crosslinking reaction. Thin films were cast from either aqueous or water-methanol solutions. The crosslinked disulfonated poly(arylene ether sulfone) networks exhibited reduced water uptake and swelling relative to their linear counterparts. SEM and AFM showed that the photo-crosslinked thin films had smooth surfaces. (C) 2016 Elsevier Ltd. All rights reserved.