Synthesis, Characterization and Thermal Degradation Study of Terpolymer-derived from p-Hydroxybenzoic Acid, Diaminonaphthelein with Formaldehyde

Abstract

Resin pHDNF has been synthesized by the condensation of p-hydroxybenzoic acid and diaminonaphthelein with formaldehyde in the presence of catalyst hydrochloric acid in 1 : 1 : 2 molar proportions of reactants. The purity of newly synthesized terpolymer has been tested and confirmed by the thin layer chromatography (TLC) technique. Detailed thermal degradation studies of the pHDNF resin have been carried out to ascertain its thermal stability. The thermal degradation curve was examined in order to determine their mode of decomposition, order of reaction, apparent activation energy, frequency factor, free energy change, entropy change and apparent energy change. The Freeman—Carroll and Sharp—Wentworth methods were applied for the calculation of kinetic parameters and the data from the Freeman—Carroll method was been used to determine various thermodynamic parameters. The terpolymer resin was characterized by elemental analysis, infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and UV-visible spectral studies. The number-average molecular weight of the resin was determined by non-aqueous conductometric titration.