Thermally assisted hydrolysis and methylation-gas chromatography of poly(aryl ether sulfone)s in the presence of tetramethylammonium hydroxide

Commercially available poly(aryl ether sulfone) resins such as poly(ether sulfone) (PES) and polysulfone (PSF) were characterized by thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) in the presence of tetramethylammonium hydroxide. The dimethyl derivative of the constituent in PES, bis(4-hydroxyphenyl)sulfone [bisphenol S, BPS], formed through selective cleavages of ether linkages with holding sulfone structures were almost exclusively observed in the chromatogram with almost quantitative recovery by THM-GC: at 300 degreesC. On the other hand, the dimethyl derivatives of the constituents in PSF, bis(4-hydroxyphenyl)isopropylidene [bisphenol A, BPA] and BPS were mostly observed in the chromatograms of PSF samples by THM-GC. Considering the high precision of the measurements achieved by this technique, the observed subtle differences in the chemical compositions among the fractionated PSF samples were interpreted in terms of the partial decomposition of the sulfone groups in PSF during the THM reaction. Thus observed results for the compositional analysis were also confirmed by matrix assisted laser desorption mass spectrometric measurements. (C) 2001 Elsevier Science B.V. All rights reserved.