Poly(phenylene) synthesized using diels-alder chemistry and its sulfonation: Sulfonate group complexation with metal counter-ions, physical properties, and gas transport

Timothy Largier, Fei Huang, Wayz Kahn, Christopher J Cornelius

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4 Scopus citations


Sulfonated poly(phenylene) (sPP) thermal stability, physical properties, and gas transport characteristics were evaluated as a function of ion-exchange capacity (x = IEC), and counter-ion type (M = H+, Cs+, Na+, Mg2+, and Al3+). Counter-ion substitution with its sulfonated groups produced Δv(SO3-) vibrational shifts that were related to ion type and valence observed using FTIR. Increasing IEC and counter ion complexation strength within sPP led to greater density and reduced fractional free volume (FFV). sPPx-M exhibited a single thermal degradation step greater than 550 °C that decreased with increasing IEC. Unsulfonated poly(phenylene) (PP) had a glass transition at 391 °C, which shifted to 420 °C upon sulfonation. Thermal stability and mechanical properties increased with counter-ion type in the following order: sPP2.5-Cs+ < sPP2.5-Na+ < sPP2.5-Mg2+. However, decreased thermal stability and physical properties were observed using Al3+ as a counter-ion (sPP2.5-Al3+). He, H2, CO2, N2, O2 and CH4 permeability decreased within sPP2.5-M based upon counter-ion type, size, and valence. Larger CO2 and H2 molecules were more permeable than He, which revealed a more complex transport process was occurring within sPP2.5. Metal-ion complexation with sPP2.5 significantly reduced CO2 and H2 permeability. PP possessed high CO2 permeability (152 Barrers) with moderate CO2/CH4 selectivity (12.6). sPP2.5-Na+ (IEC = 2.5 meq/g) had a CO2/CH4 selectivity of 71.3, and counter-ion substitution to create sPP2.5-Cs+ increased CO2/CH4 selectivity by 23%. Gas solubility and diffusivity decreased with increasing IEC and metal-ion complexation strength. sPPx-M had tunable ideal gas permselectivity that was largely a function of sulfonate group concentration and counter-ion type.

Original languageEnglish (US)
Pages (from-to)320-331
Number of pages12
JournalJournal of Membrane Science
Publication statusPublished - Feb 15 2019



  • Film thermal stability and physical properties
  • Gas transport
  • Polyphenylene and sulfonated polyphenylene
  • Sulfonate group metal-ion complexation

ASJC Scopus subject areas

  • Biochemistry
  • Materials Science(all)
  • Physical and Theoretical Chemistry
  • Filtration and Separation

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