NONISOTHERMAL DECOMPOSITION OF ANHYDROUS SILVER MALONATE

The non-isothermal decomposition of anhydrous disilver malonate was st udied up to 300-degrees-C by means of TG, DTA and DSC techniques in di fferent atmospheres (e.g. N2, H2 and air). Acetic acid, CO2, acetone a nd CO were identified as the volatile decomposition products using gas chromatography. Silver metal, on the other hand, was identified as th e final solid product using X-ray powder diffraction. The mechanism de scribed involves the breakdown of absorbed radicals, probably includin g -CH2COO- and related species, on the surface of the metallic silver product. The activation energy (DELTAE) and the frequency factor (ln A ) were calculated for the decomposition process from the variation of peak temperature (of the DTA curves) with the rate of heating (phi). T he enthalpy change (DELTAH), the heat capacity (C(p)) and entropy chan ge (DELTAS) were calculated from the DSC measurements.