Identification and characterization of dangerous self reactive substances

摘要

The handling of self reactive substances may result in serious safety problems, because their decomposition is accompanied by a high release of energy and/ or large gas generation. This is accompanied by various critical characteristics such as high deflagration potential, autocatalytic kinetics, dependence of the reaction rate on pressure etc., whereas the mechanisms are still not well understood. The characterization procedure referring to UN- transport regulations therefore prescribes a series of different tests, requiring significant amount of sample which is costly and time consuming. This is why a comprehensive model of the decomposition processes is being developed to reliably predict kinetic and heat transfer behavior of the substances under different test conditions. Newly incorporated microcalorimetry (Thermal Activity Monitor TAM) at temperatures close to transport or storage conditions provides improved prediction of the behavior of solid state self reactive substances. The applicability of a model-reduced kinetic approach to thermokinetic evaluation of solid state decomposition has been proven. These findings and the prediction of safe storage temperatures (SADT) from DTA-Onset-Temperatures for simple autocatalytic kinetics and its experimental verification are presented. By describing the effect of varying specific loadings in TAM and autoclave measurements the basis is given for modeling the influence of pressure on self- decomposition.