Applications, thermogravimetric analysis decomposition

TA instruments has developed automated thermogravimetric analysis and related kinetic programs that enable a rapid determination of decomposition rates to be made. The following excerpt from a TA application brief [57] explains the method ... 

Thermogravimetric analysis In thermogravimetric analysis (TGA) a sensitive balance is used to follow the weight change of the sample as a function of temperature. Its applications include the assessment of thermal stability and decomposition temperature, extent of cure in condensation polymers, composition and some information on sequence distribution in copolymers, and composition of filled polymers, among many others. 

In addition a thermogravimetric analysis of these polymers was carried out. Their thermal stability was evaluated in the following sequence of the onset decomposition temperature P(cgTFSI) (T = 389°C) > P(dgTFSI) (T = 382°C) > P(egTFSI) T=3Sl°C) > P(bgTFSI) (T=371°C). From these results the IL-type polymer brushes were determined to be thermally stable up to around 400°C. This is an excellent property for application to electrochemical devices. 

Usually, the thermal stability of ILs is characterized by thermogravimetrical analysis (TGA) at ambient pressure in overflow of an inert gas at a constant heating rate, typically 1-20 Kmin [41-43]. The so-called onset temperature (T gg,), at which a certain detectable mass loss of, for example, 1% is reached, is used as a synonym for the decomposition temperature to define the stability of ILs [3, 44]. The application of may be useful as a comparative value, but not as a quantitative measure of the stability due to the following reasons [25, 27] ... 

Figure 10.19 Thermogravimetric curves that exhibit decomposition starting temperature 7) and finish temperature 2. (Reproduced with permission from T. Hatakeyama and F.X. Quinn, Thermal Analysis Fundamentals and Applications to Polymer Science, 2nd ed., John Wiley Sons Ltd, Chichester. 1999 John Wiley Sons Ltd.)...

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