ASTM D471 Standard Test Method for Rubber Property - Effect of Liquids
10. Procedure for Change in Mass
10.1 Test three specimens of a single composition. Calculate the test results of the three specimens (see 17.1, Eq 1) and average the results. Weigh each specimen in air to the nearest 1 mg, record the mass as M1, and immerse in the test tube (see 8.1) containing 100 cm3 of the test liquid (see 10.1.1). Separate each test specimen from any adjacent test specimen and the walls of the test tube by approximately 6 mm (0.25 in.), for example, by perforated glass beads as shown in Fig. 1. The materials used to suspend and separate the specimens shall not affect the test liquid or the rubber.

10.1.1 Test liquids shall not be reused.

10.1.1.1 For non-volatile liquids, condition the test tube assembly at the specified temperature within the limits given in 5.1 for the specified length of time. A check of the actual temperature of the test liquid contained in the test tube should be made to ensure that the liquid is within the test temperature specified.

10.1.1.2 For volatile liquids, fit the test tube assembly with a reflux condenser (see 8.2) and condition at the specified temperature within the limits given in 5.1 for the specified length of time. A check of the actual temperature of the test liquid contained in the test tube should be made to ensure that the test liquid is within the test temperature specified.

10.2 After the immersion test has proceeded for the required length of time, remove the test specimens. If the immersion has been at elevated temperature, cool the test specimens to room temperature by transferring them to a cool clean portion of the test liquid for 30 to 60 min. Then dip the specimens quickly in acetone at room temperature, blot lightly with filter paper free of lint and foreign material, place them immediately in a tared, stoppered weighing bottle, and determine the mass after test, M2, of each specimen to the nearest 1 mg. After weighing, again immerse the test specimen in the same test liquid (see 11.2.1) if data are desired on the progressive changes that occur with increasing time of immersion. It is important that each manipulation take place promptly with the least possible lapse of time. When utilizing liquids that tend to volatilize at room temperature, no more than 30 s should elapse between removal from the test liquid and stoppering the weighing bottle.

10.3 Relatively viscous oils may be difficult to remove from the specimens with a quick acetone dip and blotting or even more vigorous wiping when the specimens are cooled in the test liquid after immersion; this can yield erroneous test results. Since these oils do not readily volatilize, specimens may be cooled by suspending them for about 30 min in air at room temperature shielded from draft, after removal from the immersion liquid at the test temperature. This will allow the majority of the oil to drip off the surface of the specimen. Then proceed with the acetone dip and blotting as described in 10.2. Report when this alternate method of specimen cooling is used.

11. Procedure for Change in Volume
11.1 Water Displacement Method for Water-Insoluble Liquids and Mixed Liquids - Test three specimens, calculate the test results for each specimen (see 17.2, Eq 2), and average the results. Obtain the mass M1 of each specimen (see 11.2.2) in air, to the nearest 1 mg, and then obtain the mass M2 of each specimen immersed in distilled water at room temperature. Quickly dip each specimen in alcohol (methanol or ethanol) to remove water (see 11.2.3), blot dry with filter paper free of lint and foreign material, and place in the immersion apparatus described in 8.1 or 8.2. Add 100 cm3 of liquid (see 10.1.1) to the test tube and complete the immersion test as described in 10.1.1.1 or 10.1.1.2. At the end of the required immersion period, remove each specimen from the test tube. Cool the specimens to room temperature by transferring them to a cool, clean portion of the test liquid for 30 to 60 min, then dip quickly in acetone at room temperature, blot lightly with filter paper free of lint or foreign material, place in a tared, stoppered weighing bottle, weigh, and record the mass as M3. Remove each specimen from the bottle, weigh in distilled water, and record the mass as M4 in immediate consecutive order to determine the water displacement after immersion (see 11.2.2 and Note 4). When data on progressive changes with increasing time of immersion are desired, dip each specimen after weighing in alcohol (methanol or ethanol) to remove water (see 11.2.3), blot dry with filter paper free of lint and foreign material, and again immerse in the same test liquid (see 11.2.1). It is important that each manipulation following removal of the test specimen from the test medium take place promptly with the least possible lapse in time. When utilizing liquids that tend to volatilize at room temperature, no more than 30 s should elapse between removal from the test liquid and stoppering the weighing bottle, and no more than an additional 30 s between removal from the weighing bottle and immersion in water.

11.2 Relatively viscous oils may be difficult to remove from the specimens with a quick acetone dip and blotting or even more vigorous wiping when specimens are cooled in the test liquid after immersion; this can yield erroneous test results. Refer to 10.3 for an alternate method of specimen cooling.

11.2.1 Report if fresh test liquid is used, which can be a requirement for certain test methods or specifications.

11.2.2 It is important that all air bubbles clinging to the test specimen be removed before weighing in distilled water. If, in the course of weighing, air bubbles appear on the surface of the specimen, or the computed volume changes 0.5 % in 5 min, the specimen is too porous to permit volume determination in this manner. In that case, the initial volume of the specimen, if the latter is a simple geometrical solid, can be determined from the overall dimensions by employing an appropriate mensuration formula, and the same procedure followed in determining the volume after the immersion test; or, if volume increase occurs principally in the thickness dimension, a simple change in thickness may be substituted for change in volume. If, in the course of weighing the test specimen floats, AISI No.316 stainless steel can be used as ballast to immerse the test specimen in the test liquid. In those cases where ballast is needed to submerge the specimen, the following procedure may be used.

11.2.2.1 Weigh the test specimen with ballast in water,

11.2.2.2 Weigh the ballast alone in water, and

11.2.2.3 Determine the difference between the weighings, and proceed with the calculations.

11.2.3 The acetone dip before and after immersion shall be omitted when water is employed as the test medium.

NOTE 4 - A jolly balance, adequately shielded from air currents, may be used for making these determinations. When utilizing liquids that tend to volatilize at room temperature, no more than 30 s should elapse between removal from the test liquid and completion of the weighing operation.

11.3 Displacement Method for Water-Soluble Liquids and Mixed Liquids (Other Than Water) - For immersion liquids that are readily miscible with water or react with it, the water displacement method as described in 11.1 may not be suitable. For such liquids that are not too viscous or volatile at room temperature, weighings for M2 and M4 may be made in the immersion liquid instead of water with weighing for M4 made in a fresh portion of the immersion liquid. These values are then used in calculating volume change using Eq 2 in 17.2. If this is not practicable, the water displacement method shall be used, except that the final weighing for M4 is omitted and change in volume is calculated according to Eq 3 in 17.2. This formula may be only approximate if the immersion liquid is a mixture, because the density of the absorbed liquid may differ from that of the bulk. Also the density of any matter extracted from the rubber may differ from that of the immersion liquid.

12. Dimensional-Change Method for Water-Insoluble Liquids and Mixed Liquids
12.1 Dimensional Change Method - Measure the original length and width of three test specimens used in 11.1 to the nearest 0.5 mm (0.02 in.) using an average of three measurements in each direction recording the dimensions as L 0 and W0, respectively. Measure the thickness of each test piece using a dial micrometer as described in 6.3 of Test Methods D412, and record as T0. Place specimens in the immersion apparatus described in 8.1 and 8.2. Add 100 cm3 of liquid (see 10.1.1) to the test tube and complete the immersion test as described in 10.1.1.1 or 10.1.1.2. At the end of the required immersion period, remove each specimen from the test tube and bring to room temperature by transferring them to a cool clean portion of the test liquid for 30 to 60 min. Dip the specimens quickly in acetone at room temperature, blot lightly with filter paper free of lint and foreign material, and promptly remeasure as described above, recording the immersed length, width, and thickness as L, W, and T, respectively. If the immersion liquid tends to volatilize at room temperature, the measurements should be completed within 30 s after removing the test specimens from the liquid at room temperature. Calculate test results according to Eq 4 in 17.3 and report the average of three specimens.

13. Procedure for Change in Mass with Liquid on One Surface Only
13.1 Scope - This test method provides a procedure for exposing thin sheet materials (rubber-coated fabrics, diaphragms, etc.) that are in contact with the immersion liquid on only one surface under definite conditions of time and temperature.

13.2 Test Specimen - A disk 60 mm (2.4 in.) in diameter and thickness of thin sheet or rubber-coated fabric being tested.

13.3 Apparatus - The essential features are illustrated in Fig. 2 and consist of a base plate, A, an open-ended cylindrical chamber, B, which is held tightly against the test specimen, C, by wing nuts, D, mounted on bolts, E. During the test, the opening in the top of the chamber is tightly closed by a suitable plug, F.

13.4 Procedure - Weigh the test specimen in air to the nearest 1 mg, record as M1, and place in the apparatus as indicated in Fig. 2. Fill the chamber of the apparatus with the test liquid to a depth of 15 mm (0.6 in.), replace plug F and complete the test at the specified conditions as described in 5.1 and 5.2. At the end of the required immersion period, bring the apparatus to standard room temperature, remove the test liquid, and release the test specimen. Remove any excess liquid from the surface by wiping or blotting with filter paper free of lint and foreign material and place the specimen immediately in a tared, stoppered weighing bottle. Determine the mass of the specimen to the nearest 1 mg and record as M2. When the immersion liquid tends to volatilize at room temperature, no more than 30 s should elapse between removal of the test specimen from the liquid and stoppering the weighing bottle. Use Eq 5 in 17.4 to calculate test results. If more than one specimen of the same composition is tested, report the result as the average.

14. Procedure for Determining Mass of Soluble Matter Extracted by the Liquid
14.1 This test method is applicable for immersions in volatile-type immersion liquids, such as ASTM reference fuels (see 6.1.2). Conduct the immersions as described in 10.1, 10.1.1.1, and 10.1.1.2. Test three specimens of a single composition, and report the result as the average. The extracted matter can be determined either by the difference in mass of the specimen before and after immersion or by evaporating the test liquid and weighing the non-volatile residue (Note 5). The mass is determined in air to the nearest 1 mg.

NOTE 5 - Both methods are subject to error. Results obtained by the mass difference of specimens before and after immersion can be affected by possible oxidation of the material during immersion. Results obtained by evaporating the test liquid may be affected by partial loss of volatile extracted material during drying. The method of choice will depend on the material under test and the test conditions. For example, the evaporation method would be preferred if further testing is to be done on the extracted matter.

14.2 Mass-Difference Method - At the end of the required immersion period, remove the test specimens from the test tube and dry to a constant mass at a temperature of approximately 40°C (104°F) and an absolute pressure of 20 kPa (150 mm Hg). Record the original mass of the test specimen before immersion as M1, the mass after immersion as M 2, and express the change in mass as a percentage of the original mass, using Eq 6 in 17.5. Report the results as the average if more than one specimen of the same composition is tested.

14.3 Evaporation Method - Transfer the liquid from the test tube in which the three test specimens have been immersed to a suitable vessel, wash the specimens in the test tube three times with 25 cm3 of fresh liquid and transfer the liquid to the same vessel. Evaporate the liquid and dry the residue to a constant mass under an absolute pressure of 20 kPa (150 mmHg) and a temperature of approximately 40°C (104°F). Record the sum of the original mass of three specimens before immersion as (∑M1, the mass of the dried residue as M3, and express M3 as a percentage of ∑M1, using Eq 7 in 17.5.

15. Changes in Tensile Strength, Elongation, and Hardness 15.1 Original Properties - The original tensile strength, ultimate elongation (Test Methods D412, Die C) and hardness (Test Methods D1415 or D2240) shall be determined, using three specimens cut from the sheet or article adjacent to those that are to be immersed in the liquid. Report results in accordance with the appropriate test method.

15.2 Immediate Deteriorated Properties - For determining the tensile strength, ultimate elongation, and hardness, prepare three test specimens from flat vulcanized sheets 2.0 +/- 0.1 mm (0.08 +/- 0.004 in.) in thickness (see 9.1) using Die C of Test Methods D 412. Measure the thickness of each test specimen, place the specimens in the test tube described in 8.1, and add 150 cm3 of liquid (see 10.1.1) to the test tube. Complete the immersion period in accordance with 10.1.1.1 or 10.1.1.2. At the end of the required immersion period, remove the specimens from the test tubes and cool immediately to room temperature in a fresh sample of the same liquid for 30 to 60 min. Then quickly dip each sample in acetone and blot lightly with filter paper that is free of lint and foreign material and immediately apply bench marks.

15.2.1 Determine the tensile strength and ultimate elongation in accordance with Test Methods D412, using the original unimmersed thickness or cross-sectional area (see 17.6, Eq 8). Determine the hardness of each immersed specimen in accordance with Test Methods D1415 or D2240. The time interval between removal from the cool liquid and testing shall be not less than 2 nor more than 3 min.

15.2.2 It may be desirable to calculate the tensile strength based on the swollen cross-sectional area. In that case Eq 9 in 17.6 shall be used. Report when this method of calculation is employed.

15.3 Relatively viscous oils may be difficult to remove from the specimens with a quick acetone dip and blotting or even more vigorous wiping when specimens are cooled in the test liquid after immersion; this can yield erroneous test results. Refer to 10.3 for an alternate method of specimen cooling.

15.4 Properties After Evaporation of Test Liquid - This test method is applicable for immersions in volatile-type immersion liquids, such as ASTM reference fuels (see 6.1.2). For determining the tensile strength, ultimate elongation, and hardness of specimens after evaporation of the immersion liquid, immerse the specimens in the test liquid in accordance with 15.2. At the end of the required immersion time, remove the specimens and, if necessary, cool them to room temperature in a fresh sample of the same liquid for 30 to 60 min.

15.4.1 For room temperature drying, suspend the specimens for 4 +/- 0.25 h in air at ambient conditions shielded from drafts. After the drying period apply bench marks and determine tensile strength and ultimate elongation in accordance with Test Methods D412 using the original thickness or cross-sectional area of the untreated specimens (see 17.6, Eq 8) and hardness according to Test Methods D1415 or D2240.

15.4.2 For determining properties after complete evaporation of the test liquid, suspend specimens after the 4-h airdrying cycle at room temperature for 20 h +/- 15 min at 70 +/- 2°C (158 +/- 4°F) in a circulating-air oven. After the heat drying cycle, remove the specimens from the oven, allow them to cool to room temperature and measure the required physical properties as described in 15.4.1. Report when the heat drying procedure is used.

15.5 The tensile strength and ultimate elongation after immersion and evaporation also can be expressed as percent change from the original values, using Eq 10 in 17.6, and hardness in unit change from the original value, according to Eq 11 in 17.6.

16. Changes in Breaking Resistance, Burst Strength, Tear Strength, and Adhesion for Coated Fabrics
16.1 Original Properties - The original properties for breaking resistance, burst strength, tear strength, and adhesion shall be determined in accordance with Test Method D751, using the specified number of specimens cut from the coated fabric adjacent to those that are to be immersed in the liquid, or, if necessary, from other pieces of coated fabric that were produced from the same lot(s) of materials under the same conditions.

16.2 Immediate Deteriorated Properties - For determining breaking resistance, burst strength, tear strength, and adhesion, prepare the number of specimens specified for each parameter in Test Method D751. Place the specimens in the test tube described in 8.1 and add 150 cm3 of liquid (see 10.1.1) to the test tube. Complete the immersion test in accordance with 10.1.1.1 or 10.1.1.2. At the end of the required immersion period, remove the specimens from the test tubes, and cool immediately to room temperature in a fresh sample of the same liquid for 30 to 60 min. Then quickly dip each specimen in acetone and blot lightly with filter paper that is free of lint or foreign material. Measure the required physical properties in accordance with Test Method D751 (see 17.7). The time interval between removal from the cool liquid and testing shall be not less than 2 min nor more than 3 min.

16.3 Relatively viscous oils may be difficult to remove from the specimens with a quick acetone dip and blotting or even more vigorous wiping when specimens are cooled in the test liquid after immersion; this can yield erroneous test results. Refer to 10.3 for an alternate method of specimen cooling.

16.4 Properties After Evaporation of Volatile Test Liquid - For determining breaking resistance, burst strength, tear strength, and adhesion of specimens after evaporation of a volatile immersion liquid, such as ASTM reference fuels (see 6.1.2), immerse the specimens in the test liquid in accordance with 15.2. At the end of the required immersion time, remove the specimens, suspend them for 2 h +/- 5 min at ambient conditions shielded from draft and then place them in a circulating-air oven at a temperature of 70 +/- 2°C (158 +/- 4°F) for a period of 2 h +/- 5 min. At the end of the drying period, remove the specimens from the oven, allow them to cool to room temperature and measure the required physical properties in accordance with Test Method D751 (see 17.7). The time interval between removal from the oven and testing shall be not less than 1 h nor more than 2 h.

16.5 If desired, report results after immersion and evaporation in percent change from the original property values, as described in 15.5.