Thermal Decomposition and Dehydration Kinetics of Tetra(piperidinium) Octamolybdate Tetrahydrate in Air

Abstract

O, was investigated in air by means of TG-DTG/DTA, DSC, TG-IR and SEM. TG-DTG/DTA curves showed that the decomposition proceeded through three well-defined steps with DTA peaks closely corresponding to mass loss obtained. Kinetics analysis of its dehydration step was performed under non-isothermal conditions. The dehydration activation energy was calculated through Friedman and Flynn-Wall-Ozawa (FWO) methods, and the best-fit dehydration kinetic model function was estimated through the multiple linear regression method. The activation energy for the dehydration step of [C 5

Thermal Behavior of Sr(II) and Ba(II)‐Diclofenac Complexes in Solid State: Study of the Dehydration and Thermal Decomposition

“…Simultaneous TG-DTA and DSC curves of Sr(Diclof) 2 For the strontium compound, the first mass loss occurs only in the stage between 30 and 100 ℃ (TG), corresponding to the endothermic peak (91 ℃) in the DTA curve due to dehydration with a loss of 12.92%. In the DSC curve the endothermic peak at 73 ℃ is also due the dehydration and in agreement with the DTA curve.…”

“…Tests with hydrochloric acid on this sample heated until the temperature indicated by the TG curve confirmed the presence of carbonate anion together with a carbonaceous residue originating from the oxidation of organic matter. Figures 3 to 6 show the TG/DTG curves for Sr(Dicl) 2 and Ba(Dicl) 2 in a nitrogen atmosphere at heating rates of 5, 10 and 20 ℃•min -1 with masses of 2 and 5 mg, which were used for the kinetic study. For barium and strontium compounds, the dehydration progressively occurs in a single stage between 35 and 90 ℃.…”

“…In Figures 7C and 7D, the diffraction lines were not observed for anhydrous compounds, which demonstrate that these compounds become non-crystalline. Scanning electron microscopy (SEM) was used to characterize the textural changes that occur after dehydration in Ba(Diclof) 2 and Sr(Diclof) 2 compounds. The images in hydrated and dehydrated conditions are shown in Figures 8 to 11, and demonstrate that the crystals of both compounds, have different shapes and sizes.…”

“…However, in this work we use the dehydration and decomposition stages technique to study and obtain information about the thermal behavior of strontium and barium-diclofenac complexes. Thus, we report on the preparation of these compounds using the general formula ML 2 •nH 2 0 (where M＝Sr or Ba, L is diclofenac and n＝number of water molecules, respectively).…”

“…metal complexes. Thus, thermal analysis reveals information on the thermal behavior, such as stoichiometry, 1 dehydration and decomposition stages, [2][3][4] energetic materials, 5,6 flame retardants, 7 and cure processes, 8 etc. However, in this work we use the dehydration and decomposition stages technique to study and obtain information about the thermal behavior of strontium and barium-diclofenac complexes.…”