Py-GC/MS and MALDI-TOF/TOF CID Study of Poly(phenyl sulfone) Fragmentation Reactions

We report a combination of the evaporation-grinding MALDI sample preparation method, MALDI-TOF/TOF CID, and Py-GC/MS to examine the fragmentation mechanisms of poly(phenyl sulfone) (PPSF). The fragmentation pattern for PPSF was compared to that of polysulfone from our previous study to test the generality of the established degradation mechanism. Py-GC/MS allowed prediction of preferred fragmentation of PPSF location based upon polysulfone fragmentation patterns and identification of four sulfide-containing fragments that were not seen in polysulfone. The identification of sulfide moieties in the Py-GC/MS of PPSF indicates that the lack of ail isopropylidene group, like that found in polysulfone, may decrease the stability the sulfone group, thus resulting in its reduction to the more stable sulfide. Our Study indicates that both poly(aryl ether sulfone)s preferentially cleave at the phenyl-sulfone bond, followed by the phenyl-oxygen bond. We were also able to make predictions on the CID fragmentation of low molecular weight linear PPSF using fragmentation patterns that were established by Py-GC/MS.