Thermal behavior of malonic acid, sodium malonate and its compounds with some bivalent transition metal ions in dynamic N2 and CO2 atmospheres

Abstract

Thermal stability and thermal decomposition of malonic acid, sodium malonate and its compounds with Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) were investigated employing simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC) in N 2 and CO 2 atmospheres and TG-FTIR in N 2 atmosphere. The thermal decomposition of malonic acid occurs with decarboxylation followed by the formation of acetic acid in both atmospheres. For sodium malonate the thermal decomposition occurs with formation of sodium carbonate, and for the transition metal malonates the final residue was: MnO (N 2 , CO 2 ),FeO (N 2 ), Fe 3 O 4 (CO 2 ), Co + CoO (N 2 ), CoO (CO 2 ), Ni (N 2 , CO 2 ), Cu (N 2 , CO 2 ) and ZnO (N 2 , CO 2 ).