Ionic poly(p-phenylene terephthalamide)s: Preparation and characterization

W. C. Chen, J. A. Sauer, M. Hara

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The preparation and characterization of two types of ionic poly(p-phenylene terephthalamide) (PPTA) is described. A sufficient number of ionic groups were added to render modified PPTA soluble in dimethylsulfoxide (DMSO). In one type, a hydrogen atom of the amide group was replaced by an ionic propanesulfonate group. In the other type, one of the hydrogen atoms on the phenylene ring was replaced by an ionic sulfonate group. The ionic PPTAs in DMSO showed an upturn in viscosity at very low concentrations that was characteristic of the polyelectrolyte behaviour. Fourier transform infrared spectra of these samples were also studied. When the ionic group was attached at the end of the short propane side chain, the intensity of both the free and hydrogen-bonded N-H stretching mode was reduced compared with that of PPTA. Depending on the location of the ionic group, there were some changes in the intensity and wave number of the asymmetric and symmetric vibrations of the ionic SO3- group and the stretching mode of the carbonyl group. In both ionic PPTAs, there was an upward shift in the frequency of the symmetric vibrations of the sulfonate ion when the counterion, having been monovalent, became divalent.

Original languageEnglish (US)
Pages (from-to)2653-2663
Number of pages11
JournalJournal of Polymer Science, Part B: Polymer Physics
Issue number21
Publication statusPublished - Nov 1 2001


All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Polymers and Plastics
  • Materials Chemistry


  • IR characterization
  • Ionic poly(p-phenylene terephthalamide)
  • Liquid-crystalline polymers
  • Polyelectrolytes
  • Solution viscosity
  • Synthesis

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