Synthesis and characterization of poly(2‐ethylaniline)–poly(styrenesulfonic acid) and poly( o ‐phenetidine)–poly(styrenesulfonic acid) complexes

This research focuses on the synthesis of ethyl and ethoxy substituted polyaniline with poly(styrenesulfonic acid) comprising a poly( o ‐phenetidine)–poly(styrenesulfonic acid) [P(OP)‐PSSA] and poly(2‐ethylaniline)–poly(styrenesulfonic acid) [P(2‐E)‐PSSA]. The complexes P(OP)‐PSSA and P(2‐E)‐PSSA were prepared by chemical polymerization of monomer ( o ‐phenetidine, 2‐ethylaniline) with PSSA using an oxidant of ammonium persulfate in 1 M HCl solution; polyaniline (PANI), poly(2‐ethylaniline) (P2E), poly( o ‐pheneditine) (POP), and polyaniline‐poly(styrenesulfonic acid) (PANI‐PSSA) also were prepared by chemical polymerization to be the reference samples. The products were characterized by IR, VIS, EPR, water solubility, elemental analysis, conductivity, SEM, and TEM. IR spectral studies shown that the structure of P(2‐E)‐PSSA and P(OP)‐PSSA complexes is similar to that of polyaniline. EPR and visible spectra indicate the formation of polarons. The morphology of the blend was investigated by measured SEM and TEM, indicating the conducting component and electrically conductive property of the polymer complexes. The pH value for deprotonation [pH ≥ 9.5 for P(2‐E)‐PSSA and pH ≥ 8.0 for P(OP)‐PSSA] are higher than that of corresponding HCl salts, indicating an intimate interaction between polymer chains. Elemental analysis results show that P(OP)‐PSSA has a nitrogen‐to‐sulfur ratio of ∼52%, larger than that for P(2‐E)‐PSSA, ∼41%. The conductivity of the complexes is around 10 −2 S/cm, and the solubility of P(2‐E)‐PSSA and P(OP)‐PSSA in water is 2.9 and 1.9 g/L, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1198–1205, 2005