ASTM E2550-21 PDF

SIGNIFICANCE AND USE 5.1 Thermogravimetry provides a rapid method for determining the thermal decomposition and reaction mass change of a material. 5.2 This test method is useful in detecting potentially hazardous reactions and in estimating the temperatures at which these reactions occur. This test method is recommended as a screening test for detecting the thermal hazards of an uncharacterized material or mixture (see Section 8). 5.3 Energetic materials, pharmaceuticals and polymers are examples of materials for which this test might be useful. This test is especially useful for materials having melting points that overlap with the onset of reaction or decomposition. Note 1: In differential scanning calorimetry (DSC), the melting endotherm may interfere with the determination of the onset temperature for reaction or decomposition. 5.4 This test is not suitable for materials that sublime or vaporize in the temperature range of interest. A sample with volatile impurities needs to be purified prior to testing by thermogravimetric analysis. Alternatively, the sample can be tested as is, however, special caution is required during the data analysis. The mass loss due to the loss of impurity should not interfere with the determination of reaction or decomposition temperature. 5.5 The four significant criteria of this test method are: the detection of a sample mass change; the extent of the mass change; the approximate temperature at which the event occurs; the observance of effects due to the atmosphere. SCOPE 1.1 This test method describes the assessment of material thermal stability through the determination of the temperature at which the materials start to decompose or react and the extent of the mass change using thermogravimetry. The test method uses minimum quantities of material and is applicable over the temperature range from ambient to 800 °C. 1.2 The absence of reaction or decomposition is used as an indication of thermal stability in this test method under the experimental conditions used. 1.3 This test method may be performed on solids or liquids, which do not sublime or vaporize in the temperature range of interest. 1.4 This test method shall not be used by itself to establish a safe operating or storage temperature. It may be used in conjunction with other test methods (for example, Test Methods E487 and E537, and Guide E1981) as part of a hazard analysis of a material. 1.5 This test method is normally applicable to reaction or decomposition occurring in the range from room temperature to 800 °C. The temperature range may be extended depending on the instrumentation used. 1.6 This test method may be performed in an inert, a reactive or self-generated atmosphere. 1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.8 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. 1.9 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.