F. Carrasco et P. Pages, THERMOGRAVIMETRIC ANALYSIS OF POLYSTYRENE - INFLUENCE OF SAMPLE WEIGHT AND HEATING RATE ON THERMAL AND KINETIC-PARAMETERS, Journal of applied polymer science, 61(1), 1996, pp. 187-197
This article studies the influence of the heating rate and sample weig
ht on the thermal decomposition of polystyrene (first-order kinetics).
For this purpose, the kinetic parameters (i.e., frequency factor and
activation energy), variables at the maximum decomposition rate (such
as conversion, reaction rate, and temperature), as well as some charac
teristic temperatures have been determined for a series of experiments
where the heating rate varies (0.5-11.5 K/min) and also, the sample w
eight (6.0-25.1 mg). Some mathematical equations have been developed t
hat allow: (1) evaluation of the activation energy of thermal decompos
ition by different ways and comparing the results obtained; (2) relati
ng different parameters between themselves, such as the heating rate w
ith the temperature at the maximum decomposition rate or the frequency
factor with the heating rate and sample weight. Finally, some theoret
ical explanations of the variation of thermal and kinetic parameters h
ave been proposed. (C) 1996 John Wiley & Sons, Inc.