ASTM D2007 for characteristic groups in processing oils & petroleum-derived oils
ASTM D2007 standard test method for characteristic groups in rubber extender and processing Oils and other petroleum-derived oils by the clay-gel absorption chromatographic method
4. Summary of Test Method
4.1 The sample is diluted with solvent and charged to a glass percolation column containing clay in the upper section and silica gel plus clay in the lower section. n-Pentane is then charged to the double column until a definite quantity of effluent has been collected. The upper (clay) section is removed from the lower section and washed further with n-pentane. A toluene-acetone mixture 50 to 50 by volume is then charged to the clay section for desorption and a specified volume of effluent collected. The lower (gel) column may be desorbed by recirculation of toluene.
4.2 The solvents are completely removed from the recovered n-pentane and the toluene-acetone fractions and the residues are weighed and calculated as saturate and polar compounds contents. Aromatics may be calculated by difference, or measured following evaporation of the toluene used for desorption of the gel column.
4.3 When the sample contains more than 0.1 mass % of n-pentane insolubles, this test method cannot be used directly. The insoluble matter must be removed from the sample prior to charging to the column. A method for this removal is given as an appendix.
4.4 Alternative methods are provided (a) for recovery of aromatics from the gel column, and (b) for analysis of oil with high-polar content.
5. Significance and Use
5.1 The composition of the oil included in rubber compounds has a large effect on the characteristics and uses of the compounds. The determination of the saturates, aromatics, and polar compounds is a key analysis of this composition.
5.2 The determination of the saturates, aromatics, and polar compounds and further analysis of the fractions produced is often used as a research method to aid understanding of oil effects in rubber and other uses.
