Synthesis, characterization, thermal degradation and electrical conductivity of poly-4-[(pyridin-2-yl-imino)methyl]benzene-1,3-diol and polymer-metal complexes
Poly-4-[(pyridin-2-yl-imino)methyl]benzene-1,3-diol (P-4-PIMBD) was synthesized via the oxidative polycondensation reaction by using sodium hypo chloride (NaOCl) oxidant in an aqueous alkaline medium at 70 oC. The yield of the polymer was found to be 68 %. The structures of the compounds were confirmed by FT-IR, UV-Vis, 1H-NMR and 13C-NMR and elemental analysis. The synthesized compounds were characterized by TGA-DTA and solubility tests. 1H and 13C NMR data shows that the polymerization proceeded by the C-C coupling of ortho and para positions according to –OH groups of 4-[(pyridin-2-yl-imino)methyl]benzene-1,3-diol (4-PIMBD). According to size exclusion chromatography (SEC) measurements, the number-average molecular weight (Mn), weight-average molecular weight (Mw) and polydispersity index (PDI) values of P-4-PIMBD were found as 9400, 12800 g mol-1 and 1.362, respectively. The polymer-metal complex compounds were synthesized with acetates salts of Cd, Co, Cu, Zn and Ni. Thermal analyses of these metal-complex compounds investigated in N2 atmosphere between 15-1000 °C. Also, FT-IR spectra and electrical conductivities of polymer-metal complexes were measured by four-point technique.
KEY WORDS: Poly-4-[(pyridin-2-yl-imino)methyl]benzene-1,3-diol, Thermal analysis, Oxidative polycondensation, Electrical conductivity
Bull. Chem. Soc. Ethiop. 2008, 22(2), 237-246.