ASTM D611 for aniline point and mixed aniline point
ASTM D611 standard test methods for aniline point and mixed aniline point of petroleum products and hydrocarbon solvents
A1. TEST METHOD A
A1.1 Apparatus
A1.1.1 The apparatus shown in Fig. A1.1 shall consist of the following:
A1.1.1.1 Test Tube, approximately 25 mm in diameter and 150 mm in length, made of heat-resistant glass.
A1.1.1.2 Jacket, approximately 37 to 42 mm in diameter and 175 mm in length, made of heat-resistant glass.
A1.1.1.3 Stirrer, manually operated, metal, approximately 2 mm in diameter (14 B&S gage) metal wire as shown in Fig. A1.1. A concentric ring shall be at the bottom, having a diameter of approximately 19 mm. The length of the stirrer to a right-angle bend shall be approximately 200 mm. The right-angle bend shall be approximately 55 mm long. A glass sleeve approximately 65 mm in length of 3-mm inside diameter shall be used as a guide for the stirrer. Any suitable mechanical device for operating the stirrer as specified is an approved alternative for the manual operation.
A1.2 Procedure
A1.2.1 Clean and dry the apparatus. Deliver 10 mL of aniline (Warning - See 7.1) and 10 mL of the dried sample (8.1) into the test tube fitted with stirrer and thermometer. If the material is too viscous for volumetric transfer, weigh to the nearest 0.01 g a quantity of the sample corresponding to 10 mL at room temperature. Center the thermometer in the test tube so that the immersion mark is at the liquid level, making sure that the thermometer bulb does not touch the side of the tube. Center the test tube in the jacket tube. Stir the mixture rapidly using a 50-mm (2-in.) stroke, avoiding the introduction of air bubbles.
A1.2.2 If the aniline-sample mixture is not miscible at room temperature, apply heat directly to the jacket tube so that the temperature rises at a rate of 1 to 3°C (2 to 5°F)/min by removing or reducing the heat source until complete miscibility is obtained. Continue stirring and allow the mixture to cool at a rate of 0.5 to 1.0°C (1.0 to 1.8°F)/min. Continue cooling to a temperature of 1 to 2°C (2.0 to 3.5°F) below the first appearance of turbidity, and record as the aniline point the temperature at which the mixture suddenly becomes cloudy throughout (Note A1.1). This temperature, and not the temperature of separation of small amounts of material, is the minimum equilibrium solution temperature.
NOTE A1.1 - The true aniline point is characterized by a turbidity that is so cloudy as to obscure the thermometer bulb in reflected light.
A1.2.3 If the aniline-sample mixture is completely miscible at room temperature, substitute a non-aqueous cooling bath for the heating source, allow to cool at the rate specified in A1.2.2 and determine the aniline point as described.
A1.2.4 Repeat the observation of aniline point temperature by heating and cooling repeatedly until a report as directed in Section 11 can be made.
