ASTM E2958-19

5.1 The activation energy may be used to calculate thermal endurance and an estimate of the lifetime of the material at specified temperatures using Test Method E1877.

5.2 The kinetic parameters determine by these test methods may be used in quality assurance, specification acceptance, research, and development.

5.3 The kinetic parameters of activation energy and logarithm of the pre-exponential factor determined by these test methods have little intrinsic value in themselves. Most practical applications of this information, such as lifetime estimation (see Test Method E1877), also require an estimation of the precision of the respective values. Determination of that precision by replicated determination is a non-manditory part of these test methods.

1.1 These test methods describe the model-free determination of Arrhenius activation energy by thermogravimetry using the factor jump (1)2 (Test Method A) or modulated thermogravimetry (2) (Test Methods B and C) techniques. With the assumption of a first-order kinetic model, the pre-exponential factor is additionally determined.

1.2 These test methods are applicable to materials with well-defined decomposition profiles, namely, a smooth, continuous mass change.

1.3 These test methods are applicable to decomposition occurring in the range from 400 K to 1200 K (nominally 100 °C to 900 °C). The temperature range may be extended depending on the instrumentation and material used.

1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.