Characterization and Thermal Decomposition of Indolylidene Aniline Azo-Dyes Derivatives

New heterocyclic azo-dyes derived from aniline derivatives using indolyl aldehyde as a coupler have been prepared and investigated by elemental analysis, IR,1H-NMR and Uv- vis spectra furthermore, the spectral properties of the dyes, solvent effect and buffer solution pH effect have been studied for determination of pKa values (9.62-12.25) for all compounds. Kinetics of differential scanning calorimetry (DSC) of these compounds were measured. The activation energy and also critical temperature (Tc), glassy transition temperature (Tg) and melting point (Tm) temperatures were calculated.