The thermal decomposition of electrolytic manganese dioxide (EMD), in an inert atmosphere, and the effect of chemical reduction on EMD, using 2-propanol under reflux (82°C), was investigated by differential scanning calorimetry (DSC). This study is an extension of a study investigating the thermal decomposition of EMD and reduced EMD by TG-MS (J. Therm. Anal. Cal., 80 (2005)625)). The DSC characterisation was carried out up to 600°C encompassing the water loss region up to 390°C and the first thermal reduction step. Water removal was observed in two distinct endothermic peaks (which were not deconvolved in the TG-MS) associated with the removal of bound water. For the lower degrees of chemical reduction, thermal reduction resulted in the formation of Mn₂O₃; for higher degrees of chemical reduction, the thermal reduction resulted in Mn₃O₄ at 600°C. In the DSC the thermal reduction of the EMD and chemically reduced specimen was observed to be endothermic. The reduced specimens, however, also showed an exothermic structural reorganisation.
Journal of Thermal Analysis and Calorimetry Vol. 88, Issue 1, p. 177-180