The Long-term Stability of Sodium Percarbonate in Presence of Zeolite as Measured by Heat Flow Calorimetry

摘要

Heat flow calorimetry has been evaluated as an alternative technique to conventional stability testing of sodium percarbonate [15630-89-4] (SPC) based on analysis of the hydrogen peroxide content.Stability tests were performed with different SPC samples as well as under various experimental conditions.In general,stable samples exhibiting high concentration of hydrogen peroxide were accompanied by low heat flow values.It was found that the results obtained by heat flow calorimetry and conventional stability testing were in agreement.It was also demonstrated that the long-term stability could be predicted from heat flow data obtained during the initial stage of decomposition.Furthermore,different manufacturing and experimental conditions were manifested as a change of the heat flow curve.The results indicate that the rate of heat production is closely associated with the stability of sodium percarbonate,i.e.the rate of decomposition of sodium percarbonate.In presence of zeolite the stability of sodium percarbonate was reduced,particularly under humid conditions.