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Keywords:

  • oxidative polycondensation;
  • poly-4-[(4-methylphenyl)iminomethyl]phenol;
  • air O2;
  • NaOCl;
  • H2O2;
  • thermal analysis;
  • conductivity and band gap

Abstract

In this study, the oxidative polycondensation reaction conditions of 4-[(4-methylphenyl)iminomethyl]phenol (4-MPIMP) were studied by using oxidants such as air O2, H2O2, and NaOCl in an aqueous alkaline medium between 50 and 90°C. The structures of the synthesized monomer and polymer were confirmed by FTIR, UV–vis, 1H–13C-NMR, and elemental analysis. The characterization was made by TGA-DTA, size exclusion chromatography (SEC), and solubility tests. At the optimum reaction conditions, the yield of poly-4-[(4-methylphenyl)iminomethyl]phenol (P-4-MPIMP) was found to be 28% for air O2 oxidant, 42% for H2O2 oxidant, and 62% for NaOCl oxidant. According to the SEC analysis, the number–average molecular weight (Mn), weight–average molecular weight (Mw), and polydispersity index values of P-4-MPIMP were found to be 4400 g mol−1, 5100 g mol−1, and 1.159, using H2O2, and 4650 g mol−1, 5200 g mol−1, and 1.118, using air O2, and 5100 g mol−1, 5900 g mol−1, and 1.157, using NaOCl, respectively. According to TG analysis, the weight losses of 4-MPIMP and P-4-MPIMP were found to be 85.37% and 72.19% at 1000°C, respectively. P-4-MPIMP showed higher stability against thermal decomposition. Also, electrical conductivity of the P-4-MPIMP was measured, showing that the polymer is a typical semiconductor. The highest occupied molecular orbital and the lowest unoccupied molecular orbital energy levels and electrochemical energy gaps (Emath image) of 4-MPIMP and P-4-MPIMP were found to be −5.76, −5.19; −3.00, −3.24; 2.76 and 1.95 eV, respectively. According to UV–vis measurements, optical band gaps (Eg) of 4-MPIMP and P-4-MPIMP were found to be 3.34 and 2.82 eV, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007