Synthesis, characterization, thermal degradation and electrical conductivity of poly-4-[(pyridin-2-yl-imino)methyl]benzene-1,3-diol and polymer-metal complexes

Abstract

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 (M_n), weight-average molecular weight (M_w) 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.