OIL CONTENT OF PETROLEUM WAXES: ASTM D721
EXPLANATION
The oil content of a wax may have significant effects on several of its properties such as strength, hardness, flexibility, scuff resistance, coefficient of friction, coefficient of expansion, melting point, and oil straining. The importance of these effects may be dependent upon the ultimate use of the wax. This test method determines the oil content of the petroleum waxes with a congealing point of 30° C (86° F) or higher as determined by the Test Method ASTM D938, and containing no more than 15 % of oil. With some types of waxes of oil content greater than 5 %, there may be incompatibility with methyl ethyl keytone (MEK) resulting in the formation of two liquid phases. In such cases this test method cannot be used.
TEST SUMMARY
A wax sample is dissolved in methyl ethyl ketone (MEK), the solution cooled to -32° C (-25° F) to precipitate the wax, and filtered. The oil content of the filtrate is determined by evaporating the MEK solvent and weighing the residue.
TEST PRECISION
Repeatability: 0.06 + 8 % of the mean
Reproducibility: 0.2 + 11 % of the mean
This test method has no bias.
