The pyrolysis of metal acetates

The thermal decomposition of a selection of group II metal acetates has been examined in atmospheres of nitrogen and of oxygen, using DTA, TG and X-ray diffraction techniques, illustrating the variety of solid phases appearing during the decomposition process. X-ray amorphous intermediates were detected in the dehydration of hydrated magnesium and cadmium acetates, the anhydrous acetate at least partially melting prior to decomposition. Under oxygen the pyrolytic decomposition proceeded generally with fewer intermediate stages than observed under non-oxidative conditions, with the major exothermal decomposition process occurring at somewhat lower temperatures. Combining these results with earlier data on strontium and zinc acetates, at 500°C the decomposition products were the corresponding oxides, except in the case of barium and strontium acetates where the carbonates were produced. The sensitivity of the thermal decomposition processes to sample configuration and to the effect of possible product accumulation appears to underlie much of the controversy regarding these processes which exists in the literature.