Thermogravimetric study of thermal degradation of polyetherimide

Abstract

Thermal stability in nonoxidizing atmosphere of a polyetherimide (PEI) is investigated by thermogravimetry (TG). It is observed that thermal degradation of this product consists of two overlapping processes, which are conveniently separated by fitting the TG curves to mixtures of generalized logistic functions. Thus, each process is represented by a single function. The analysis of the fitting parameter values obtained for the main degradation process in different isothermal and heating ramp conditions allows to obtain insightful kinetic parameters (critical temperature, energy barrier, and reaction-order) which allow to make predictions in both isothermal and nonisothermal contexts. There is a minimum temperature for each process to occur and a ramp-energy barrier related to the process rate. In the ramp context, the values of these two parameters explain that, although one process starts at lower temperature, it proceeds at a very low rate until reaching temperatures at which the other process goes much faster. V C 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42329.

Kinetics of Thermal Degradation of Cellulose: Analysis Based on Isothermal and Linear Heating Data

“…Energy barrier values obtained for other processes and materials, assuming the same model as in the present work, were recently reported by the authors Zaragoza et al 2015). In this context, the true energy barrier value obtained here, 13 kJ mol -1 , was on the same order as those obtained for the main degradation step of some acrylic-based copolymers (approximately 11 kJ mol -1 ) and polyetherimide (22 kJ mol -1 ), as displayed in Table 4.…”

“…The approach used here has been explained in some recent works of the authors Zaragoza et al 2015). Time derivatives of generalised logistic functions were assumed to represent the rate of single mass loss processes, both for linear heating and for isothermal conditions,…”

“…A method developed by the authors (López-Beceiro et al 2013Zaragoza et al 2015) was used to that aim. The method implies fitting derivative thermogravimetric (DTG) curves obtained in a set of varied isothermal and non-isothermal conditions.…”

Thermal Degradation and Fire Behavior of High Performance Polymers

“…Thermogravimetric analyses (TGA) of PEI at different heating rates, in air and in inert atmospheres were also reported [19][20][21][22][23] Figure 3 shows the TGA plot of Ultem with a heating rate of 10 °C/min. It was reported that the onset of the degradation occurs at around 450 °C under nitrogen [23,24]. The maximum rate of decomposition temperature is about 510 °C (DTG curve).…”

“…In addition to making the determination of the different decomposition temperatures possible, TGA also provides a way to determine the kinetic parameters for the thermal decomposition of a material. The kinetic parameters of the thermal degradation of PEI has been thoroughly studied in the past [20,24,27]. One of the first works concerning the kinetics of the thermal decomposition of PEI consisted in using thermogravimetry at different heating rates under nitrogen [20].…”