Syntheses and characterizations of multifunctional polyphenols derived from dihydroxyphenylene-based Schiff bases

摘要

Schiff base compounds were synthesized by condensation reaction of 1,4-diamino-benzene, naphthalene-l,5-diamine and 2,6-dichlorobenzene-1,4-diamine compounds with 2,4-di-hydroxybenzaldehyde. The obtained Schiff bases were converted to their polyphenol derivatives by oxidative polycondensation. Sodium hypochlorite and air were used as the oxidants. Experi-mental parameters such as temperature, reaction time and oxidant concentration were varied to determine the optimum oxidative polycondensation conditions. The structures of all compounds were confirmed by FT-IR, UV-Vis and ~1H- and ~(13)C NMR analyses. In addition, thermal properties of the Schiff bases and the corresponding polymers were determined by TG-DTA, DSC and DMA techniaues. Photoluminescence properties of the synthesized compounds were determined in DMF solutions. Electrochemical characterizations were made by cyclic voltammetry measure-ments. Solid state conducthdties of the polymers were determined by four point probe techniaue using an electrometer. The number average and weight average molecular weights and polydis-persity index values of the synthesized compounds were determined by the size exclusion chroma-tography.