Synthesis, characterization, thermal stability, conductivity, and band gap of a new aromatic polyether containing an azomethine as a side
✍ Scribed by İsmet Kaya; Mehmet Yıldırım
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 313 KB
- Volume
- 106
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
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 O~2~, H~2~O~2~, 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, ^1^H–^13^C‐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 O~2~ oxidant, 42% for H~2~O~2~ oxidant, and 62% for NaOCl oxidant. According to the SEC analysis, the number–average molecular weight (M~n~), weight–average molecular weight (M~w~), and polydispersity index values of P‐4‐MPIMP were found to be 4400 g mol^−1^, 5100 g mol^−1^, and 1.159, using H~2~O~2~, and 4650 g mol^−1^, 5200 g mol^−1^, and 1.118, using air O~2~, 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 (E) 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 (E~g~) 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