Differential thermal analysis under quasi-isothermal, quasi-isobaric conditions (Q-DTA): Part II. Water evaporation and the decomposition mechanism of compounds with structural and crystal water

• Published in: Thermochimica acta Vol. 424; no. 1-2; pp. 75 - 82
• Main Authors: Paulik, F., Bessenyey-Paulik, E., Walther-Paulik, K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.12.2004; Elsevier Science
• Subjects: Analytical chemistry; Chemical and thermal methods; Chemistry; CRTA heating control; Exact sciences and technology; Q-DTA; Q-TG method; Quasi performing the thermodynamic claims; Quasi-static: TGHC; Quasi-static: TGHC; Q-TG method; CRTA heating control; Quasi performing the thermodynamic claims; Q-DTA; Water; Calcium Compounds; Crystals; Differential thermal analysis; Evaporation; Copper II Sulfates; Dehydration; Dehydroxylation; Thermodynamics; CRTA healing control; Reaction mechanism; Thermal analysis; Hydrates
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/j.tca.2004.03.018

It is already a generally accepted opinion today that the course of DTA, DSC and TG curves is deteriorated by the non-isothermal heating control and by other experimental conditions to such an extent that it is more characteristic for the experimental conditions, than for the transformation itself. This problem can be eliminated completely by the simultaneous use of “transformation-governed heating control” (TGHC) and “self-generated atmosphere” (SGA) ensuring quasi-isothermal, quasi-isobaric conditions for the DTA measuring technique (Q-DTA). This experience is proven on the examples of the evaporation of water under boiling, the dehydration of Ca(OH)2, CuSO4·5H2O, CaBr2·6H2O, Mg(OH)2 and CaSO4·2H2O by providing both, the results obtained by the DTA, TG and the Q-DTA measuring techniques.