Controlled rate thermal analysis commanded by mass spectrometry for studying the kinetics of thermal decomposition of very stable solids

A quadrupole mass spectrometer coupled to a thermobalance has been used to develop a controlled rate thermal analysis (CRTA) equipment This instrument maintains constant the partial pressure of the gas generated in a solid-gas reaction during the entire process while recording the weight loss along the process This system permits to perform the kinetic analysis of the thermal decomposition of very stable compounds with a very low equilibrium pressure in the temperature range at which the reaction takes place The performance of the equipment was checked by studying the kinetics of the thermal decomposition of BaCO3 using for the control the CO2 partial pressure Both the activation energy and the reaction kinetic model has been calculated. (C) 2002 Wiley Periodicals, Inc.