Combined facile methods of the DSC and origin lab program to study the dehydration kinetics of KMnPO4·H2O

Abstract

Thermal dehydration kinetics of potassium manganese phosphate monohydrate (KMnPO4·H2O) was studied using alternative procedure, including the combination between DSC data and Origin Lab program. The results revealed that this convenient method is a suitable tool for the determination of reliable kinetic parameters. The peak area at current temperature can be calculated using the Origin Lab program. Consequently, the kinetic parameters by non-isothermal equations can be calculated. The apparent activation energies were found to be 101.26 and 101.45 kJ mol−1 using KAS and iterative methods, respectively. The natural logarithms of pre-exponential factor (lnA) were found to be 12.2775 and 12.4157, respectively based on mechanism function of g(α) = (1−(1 – α)2/3). The experimental enthalpy change of the dehydration process of the studied compound was about 290 J g−1. All detectable peaks from XRD patterns of this compound are indexed as the formula KMnPO4·H2O according to the standard data file PDF#802360. The SEM micrograph exhibits the loose agglomeration phenomenon among the thin plate, which supports the existence of the layered structure compound.