Standard Test Methods for Volatility Rate by Thermogravimetry

Importancia y uso:

5.1 Volatility of a material is not an equilibrium thermodynamic property but is a characteristic of a material related to a thermodynamic property that is vapor pressure. It is influenced by such factors as surface area, temperature, particle size, and purge gas flow rate; that is, it is diffusion controlled.

5.2 The extent of containment achieved for specimens in these test methods by means of a pinhole opening between 0.33 mm to 0.38 mm allows for measurement circumstances that are relatively insensitive to experimental variables other than temperature. Decreasing the extent of containment by use of pinholes larger than 0.38 mm will increase the magnitude of the observed rate of mass loss but will also reduce the measurement precision by increasing the sensitivity to variations in other experimental variables.

5.3 Results obtained by these test methods are not strictly equivalent to those experienced in processing or handling conditions but may be used to rank materials for their volatility in such circumstances. Therefore, the volatility rates determined by these test methods should be considered as index values only.

5.4 The volatility rate may be used to estimate such quantifiable values as drying interval or the extent of volatile release from a process.

Subcomité:

E37.01

Volúmen:

14.01

Número ICS:

19.020 (Test conditions and procedures in general), 71.040.50 (Physicochemical methods of analysis)

Palabras clave:

mass loss; thermogravimetric analysis (TGA); thermogravimetry (TG); volatility; volatility rate;