MALDI-TOF MS Study of Poly(p-phenylene sulfide)

A combination of the evaporation-grinding MALDI-TOF MS sample preparation method with surface-modification techniques is presented for the characterization of intractable poly(p-phenylene sulfide)s (PPS). Studies focus on the relationships between the following experiments: (1) effects of MALDI laser fluence and area of irradiation on model PPS phenyl-capped trimers and cyclics; (2) modification of PPS synthesis conditions; (3) thermal curing of PPS under various atmospheric (N2 and air) and thermal (100−300 °C) conditions; and (4) heated N-methyl-2-pyrrolidone fractionation of high MW PPS (25, 50, 75, and 100 °C). These studies yielded a wealth of information on the mass, structure, and end groups of species generated in the synthesis, postsynthesis modification, and thermal curing of PPS. Furthermore, surface-modified MALDI sample preparation techniques were shown to selectively isolate cyclic species from high-molecular-weight PPS.