Poly(arylene ether)s derived from N-alkyl-N-phenyl-3,5-difluorobenzene sulfonamides: Effect of alkyl chain length on the glass transition temperature

Using N-phenyl-3,5-difluorobenzene sulfonamide, prepared in one-step from 3,5-difluorobenzenesulfonyl chloride, as the starting material a series of N-alkyl-N-phenyl-3,5-difluorobenzene sulfonamide monomers, with chain lengths of 1–12 carbon atoms was synthesized. The monomers were subjected to meta-activated nucleophilic aromatic polycondensation reactions, with Bisphenol-A as the nucleophilic reaction partner, to convert them to the corresponding poly(arylene ether)s. The polymer structures were characterized by 1H and 13C NMR spectroscopy, size exclusion chromatography, thermogravimetric analysis, and differential scanning calorimetry. The effect of alkyl chain length on the thermal stability and glass transition temperatures, Tg, values was determined. The thermal stability of the polymers was not very sensitive to the nature of the alkyl group as degradation onset temperatures ranged from 359 to 370 °C. The Tg values covered a much wider range with the methyl and dodecyl derivatives displaying values of 122 and 46 °C, respectively.

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