The synthesis and characteristics of sulfonated poly(phenylene sulfide)

Abstract

In this work, the soluble poly[methyl[4-(phenylthio)phenyl]sulfonium trifluoromethanesulfonate] (PPST) in organic solvents was synthesized by self-condensation polymerization of methyl-(phenylthio)phenyl sulfoxide. Sulfonated poly(phenylene sulfide) (SPPS) was prepared by sulfonating PPST with fumic sulfonic acid (10% SO3-H2SO4) and demethylation with aqueous NaOH solution. The optimum conditions of the sulfonation of PPS which was determined by ion exchange capacity and IR absorbance were reaction time of 12 hr and reaction temperature at 150 degrees C. Ion exchange capacities of SPPS measured by IR spectroscopy was 11.5 meq/g and the degree of sulfonation per repeating unit was 2.19. The sulfonation reaction above 150 degrees C resulted in a decrease in the degree of sulfonation because the crosslinking reaction took place through dehydration between the sulfonic acid and near phenyl groups. As PPS was sulfonated, glass temperature (T-g) increased and initial degradation temperature decreased.