Thermal Study in Solid State of Zn(II)‐Diclofenac Complex: Behavior Kinetic of the Dehydration, Transition Phase and Thermal Decomposition

Abstract

AbstractThe dehydration, thermal decomposition and transition phase stage of Zn(II)‐diclofenac compound were studied by simultaneous TG‐DTA and DSC techniques. The TG and DSC curves of this compound were obtained with the mass of sample of 2 and 5 mg. Additionally, DSC curves were carried out in opened and closed α‐alumina pans under static and nitrogen atmosphere. The DTA and DSC curves show that this compound possesses exothermic transition phase between 170‐180 °C, which it is irreversible (monotropic reaction). The kinetics study of this transition phase stage was evaluated by DSC under non‐isothermal conditions. The obtained data were evaluated with the isoconversional method, where the values of activation energy (Ea / kJ mol−1) was plotted in function of the conversion degree (α). The results show that due to mass sample, different activation energies were obtained. From these curves a tendency can be seen where the plots maintain the same profile for closed lids and almost run parallel to each other.