Synthesis and characterization of polyphenol derived from Schiff bases containing methyl and carboxyl groups in the structure

Abstract

In this study, a series of Schiff bases (CBAA4MP, CBAA5MP, and CBAA3MP) which differ from each other based on the position of methyl group were synthesized. The derived monomers were changed into their polymer kind (P-CBAA4MP, P-CBAA5MP, and P-CBAA3MP) by oxidative polycondensation in aqueous alkaline medium using NaOCl as the oxidant. The structures of the synthesized compounds were enlightened using FT-IR, UV-vis, 1H-NMR, and 13C-NMR analyses. The 1H-NMR and 13C-NMR results showed that polymerization preceded by C-C and C-O-C couplings of the monomer units (phenylene and oxyphenylene groups). The molecular weight dispersion of the polymers was designated by size exclusion chromatography analysis. Electrochemical (E′g) and optical (Eg) band gaps of the synthesized substances are measured using CV and UV-vis techniques, in order of. Solid state electrical conductivities of both doped and undoped states of the synthesized polymers were evaluated. Also, the effects to the electrochemical band gaps values of ortho, meta, and para positions of methyl group in the structures of polymers were examined from CV measurements.