Standard Test Method for Reaction Induction Time by Thermal Analysis

Importancia y uso:

5.1 This test method measures the time to extrapolated onset of an exothermic reaction under constant temperature (isothermal) conditions for reactions which have an induction period, for example, those which are catalytic, autocatalytic, or accelerating in nature or which contain reaction inhibitors.

5.2 The RIT determined by this test method is an index measurement that is useful for comparing one material to another at the test temperature of interest and in the same apparatus type only.

5.3 This test method is a useful adjunct to dynamic thermal tests, such as Test Method E537, which are performed under conditions in which the sample temperature is increased continuously at constant rate. Results obtained under dynamic test conditions may result in higher estimates of temperature at which an exothermic reaction initiates because the detected onset temperature is dependent upon the heating rate and because dynamic methods allow insufficient time for autocatalytic reactions to measurably affect the onset temperature.

5.4 RIT values determined under a series of isothermal test conditions may be plotted as their logarithm versus the reciprocal of the absolute temperature to produce a plot, the slope of which is proportional to the activation energy of the reaction as described in Test Methods E2070.

5.5 This test method may be used in research and development, manufacturing, process and quality control, and regulatory compliance.

5.6 This test method is similar to that for oxidation induction time (OIT) (for example, Specification D3350 and Test Methods D3895, D4565, D5483, D6186, and E1858) where the time to the oxidation reaction under isothermal test conditions is measured. The OIT test method measures the presence of antioxidant packages and is a relative measurement of a material’s resistance to oxidation.

Subcomité:

E27.02

Referida por:

E2070-23, E1445-08R23

Volúmen:

14.01

Número ICS:

17.200.20 (Temperature-measuring instruments)

Palabras clave:

differential scanning calorimetry (DSC); differential thermal analysis (DTA); hazard potential; reaction induction time (RIT); reactions, thermal; thermal analysis (TA); thermal stability;