A new Schiff base epoxy oligomer resin: Synthesis, characterization, and thermal decomposition kinetics



Oligo{2,2′-{1,4-phenylenebis[nitrilomethylylidene]}bis(6-methoxyphenol)} (OPNMMP) was synthesized from o-vanillin and p-phenylene diamine by oxidative polycondensation with NaOCl in an aqueous alkaline. Then, a new Schiff Base epoxy oligomer resin, OPNMMP–epichlorohydrine (EPC), was produced with EPC. The structures of the resulting compounds were confirmed by Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, 1H-NMR, and 13C-NMR. Further characterization processes were preformed by thermogravimetry (TG)–differential thermal analysis, gel permeation chromatography, and solubility testing. Also, the kinetics of the thermal decomposition of OPNMMP–EPC were investigated by thermogravimetric analysis. The TG curves showed that the thermal decomposition of OPNMMP–EPC occurred in one stage. The kinetic parameters related to the decomposition kinetics of OPNMMP–EPC were obtained from TG curves with the following methods: Friedman, Flynn–Wall–Ozawa, Kissinger, invariant kinetic parameter, and Coats–Redfern (CR), under an N2 dynamic atmosphere and different heating rates (5, 10, 15, and 20°C/min). The mechanism function and pre-exponential factor were also determined by a master plots method. The apparent activation energies of the thermal decomposition were calculated from these methods for OPNMMP–EPC. The analysis of the results obtained by the CR and master plots methods showed that the decomposition mechanism of OPNMMP–EPC in N2 was a deceleration-type mechanism. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011