Effect of substituents on thermal behavior of some symmetric double schiff’s bases containing a cardo group

Abstract

Thermal behavior of symmetric double schiff’s bases containing cardo group has been studied by TGA and DSC techniques at 10°C/min in nitrogen atmosphere. DSC transitions, thermal stability and kinetic parameters are affected by nature and position of substituents. Schiff’s bases are thermally stable between 173-272°C and followed either a single step or two steps degradation (fractional or integral order). Different magnitudes of n, E and A suggested different degradation mechanisms. A large and negative magnitudes of “S* confirmed highly ordered transition state, while positive magnitudes of “S* confirmed less ordered transition state.