The oxidative polycondensation of 2-[(4-pyridilmethylene)-imino]phenol by molecular O2 in alkaline medium: Synthesis and characterization

Summary The polymer of 2-[(4-pyridilmethylene)-imino] phenol (2-PIP) has been formed from the oxidative polycondensation (OP) reaction by using molecular O₂ as the oxidant in an aqueous alkaline medium between 60–90 °C. The optimum reaction conditions and the main parameters of the process were determined. The yield of polymer was found as 50.1%. The structures of synthesized monomer and polymer were confirmed by FT-IR, UV-vis, ¹H-¹³C-NMR and elemental analysis. The characterization was made by TGA-DTA, size exclusion chromatography (SEC) and solubility tests. The ¹H-¹³C-NMR data shows that the polymerization proceeded with C-C and C-O-C coupling system of ortho and para positions and oxyphenylene according to –OH group of 2-PIP. The molecular weight distribution values of the product were determined from SEC measurement. The number-average molecular weight (M_n), weight-average molecular weight (M_w) and polydispersity index (PDI) values of poly-2-[(4-pyridilmethylene)-imino]phenol (poly-2-PIP) were found to be 11350, 12600 g.mol^-1 and 1.110, respectively. According to thermo gravimetric analysis (TGA), the carbon residues of 2-PIP and poly-2-PIP were found to be 18.17% and 45.10%, respectively, at 1000 °C.