THERMAL-DECOMPOSITION OF METAL FORMATES .2. SOLID-STATE THERMAL-DECOMPOSITION STUDIES ON MAGNESIUM FORMATE DIHYDRATE

Magnesium formate dihydrate has been synthesized by the action of formic acid on anhydrous magnesium oxide. This product analysed as Mg(COOH)2 · 2H2O. Its mode of thermal decomposition has been studied by thermal methods of analysis including simultaneous DTA/mass spectrometry. Nitrogen adsorption surface area of the solid products at various stages of its decomposition have been obtained. X-Ray diffraction and scanning electron micrographs have also been used to interpret the results. The decomposition of magnesium formate took place in three stages, which includes a phase change, at 265°C. The endotherm at 430°C changed to an exotherm in the presence of air; it corresponded to the decomposition of a new anhydrous phase of magnesium formate. The effect of the sample holder and changing atmospheres on the DSC analysis has been investigated. A scheme is presented for the thermal decomposition. © 1979.