Thermal Behavior and Mass Spectrometry Studies of p-Bis(2-oxooxazolidin-5-ylmethoxy)benzene

Abstract

P-Bis(2-oxooxazolidin-5-ylmethoxy)benzene (PBOB) was prepared by the reaction of tris(2, 3-epoxypropyl)isocyanurate with hydroquinone in the presence of sodium hydroxide as a catalyst in reflux solution of N, N-dimethylformamide. The thermal behavior and the cleavage mechanism by electron impact for PBOB were investigated with the thermal analysis and mass spectrometry, respectively. PBOB gave dimorphic crystals, high temperature- and low temperature-forms. In solid phase two forms gave the identical IR and NMR spectra, b ut they showed marked differences in X-ray diffraction patterns and the activation energies. The activation energies of the pyrolysis was calculated from the TG curves to be 140-460kJ/mol at the high temperature-form and 130-150 kJ/mol at the low temperature -form, respectively. No difference in the pyrolytic behavior was observed in these two forms. In the cleavage by electron impact for PBOB the molecular ion peak was recognized as the base peak. From the TG-GC/MS measurements, the difference between El-cleavage and thermal decomposition for PBOB was elucidated.