ASTM D471 – 98

Designation: D 471 – 98e1 Standard Test Method for Rubber Property—Effect of Liquids1 This standard is issued under the fixed designation D 471; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense. e1 NOTE—Table 3 was editorially updated in September 1999. 1. Scope 1.1 This test method covers the required procedures to evaluate the comparative ability of rubber and rubber-like compositions to withstand the effect of liquids. It is designed for testing: ( 1) specimens of vulcanized rubber cut from standard sheets (see Practice D 3182), (2) specimens cut from fabric coated with vulcanized rubber (see Test Method D 751), or (3) finished articles of commerce (see Practice D 3183). This test method is not applicable to the testing of cellular rubbers, porous compositions, and compressed sheet packing, except as described in 11.2.2. 1.2 ASTM Oils No. 2 and No. 3, formerly used in this test method as standard test liquids, are no longer commercially available and in 1993 were replaced with IRM 902 and IRM 903, respectively (see Appendix X1 for details). 1.3 This test method includes the following: Change in Mass (after immersion) Section 10 Change in Volume (after immersion) Section 11 Dimensional-Change Method for Water-Insoluble Liq- uids and Mixed Liquids Section 12 Change in Mass with Liquid on One Surface Only Section 13 Determining Mass of Soluble Matter Extracted by the Liquid Section 14 Change in Tensile Strength, Elongation and Hardness (after immersion) Section 15 Change in Breaking Resistance, Burst Strength, Tear Strength and Adhesion for Coated Fabrics Section 16 Calculation (of test results) Section 17 1.4 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety and health practices and determine the applica- bility of regulatory limitations prior to use. 2. Referenced Documents 2.1 ASTM Standards: D 92 Test Method for Flash and Fire Points by Cleveland Open Cup2 D 97 Test Method for Pour Point of Petroleum Products2 D 287 Test Method for API Gravity of Crude Petroleum and Petroleum Products (Hydrometer Method)2 D 412 Test Methods for Vulcanized Rubber and Thermo- plastic Rubbers and Thermoplastic Elastomers— Tension3 D 445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and the Calculation of Dynamic Viscosity)2 D 611 Test Methods for Aniline Point and Mixed Aniline Point of Petroleum Products and Hydrocarbon Solvents2 D 751 Test Methods for Coated Fabrics4 D 975 Specification for Diesel Fuel Oils2 D 1217 Test Method for Density and Relative Density (Specific Gravity) of Liquids by Bingham Pycnometer2 D 1415 Test Method for Rubber Property—International Hardness3 D 1500 Test Method for ASTM Color of Petroleum Prod- ucts (ASTM Color Scale)2 D 1747 Test Method for Refractive Index of Viscous Mate- rials2 D 2008 Test Method for Ultraviolet Absorbance and Ab- sorptivity of Petroleum Products2 D 2140 Test Method for Carbon-Type Composition of In- sulating Oils of Petroleum Origin5 D 2240 Test Method for Rubber Property—Durometer Hardness3 D 2699 Test Method for Research Octane Number of Spark-Ignition Engine Fuel6 D 3182 Practice for Rubber—Materials, Equipment, and Procedures for Mixing Standard Compounds and Prepar- ing Standard Vulcanized Sheets3 D 3183 Practice for Rubber—Preparation of Pieces for Test Purposes from Products3 D 4483 Practice for Determining Precision for Test Method Standards in the Rubber and Carbon Black Industries3 1 This test method is under the jurisdiction of ASTM Committee D-11 on Rubber and is the direct responsibility of Subcommittee D11.15 on Degradation Tests. Current edition approved November 10, 1998. Published December 1998. Originally published as D 471 – 37 T. Last previous edition D 471 – 97. 2 Annual Book of ASTM Standards, Vol 05.01. 3 Annual Book of ASTM Standards, Vol 09.01. 4 Annual Book of ASTM Standards, Vol 09.02. 5 Annual Book of ASTM Standards, Vol 10.03. 6 Annual Book of ASTM Standards, Vol 05.05. 1 Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States. D 4485 Specification for Performance Engine Oils7 D 4678 Practice for Rubber– Preparation, Testing, Accep- tance, Documentation, and Use of Reference Materials3 D 5900 Specifications for Physical and Chemical Properties of Industry Reference Materials (IRM)3 E 145 Specification for Gravity-Convection and Forced- Ventilation Ovens8 2.2 SAE Standards:9 J 300 Engine Oil Viscosity Classification 3. Summary of Test Method 3.1 This test method provides procedures for exposing test specimens to the influence of liquids under definite conditions of temperature and time. The resulting deterioration is deter- mined by measuring the changes in physical properties, such as stress/strain properties, hardness, and changes in mass, volume, and dimension, before and after immersion in the test liquid. 3.2 The precision statement in Section 19 is based on an interlaboratory test program run in 1981, using six different rubbers with ASTM Reference Fuels B, C, D10 and ASTM Oils No. 1 and No. 3. 3.3 The precision statement in Appendix X2 is based on an interlaboratory test program conducted in 1993 to establish replacements for ASTM Oils No. 2 and No. 3. Because of the limited number of participating laboratories, only repeatability could be evaluated, and it was necessary to use pooled values of four No. 2 type oils (No. 2 plus three candidate replacement oils) and four No. 3 type oils (No. 3 plus three candidate replacement oils). Twelve rubbers were tested in this program. 4. Significance and Use 4.1 Certain rubber articles, for example, seals, gaskets, hoses, diaphragms, and sleeves, may be exposed to oils, greases, fuels, and other fluids during service. The exposure may be continuous or intermittent and may occur over wide temperature ranges. 4.2 Properties of rubber articles deteriorate during exposure to these liquids, affecting the performance of the rubber part, which can result in partial failure. 4.3 This test method attempts to simulate service conditions through controlled accelerated testing, but may not give any direct correlation with actual part performance, since service conditions vary too widely. It yields comparative data on which to base judgment as to expected service quality. 4.4 This test method is suitable for specification compliance testing, quality control, referee purposes, and research and development work. 5. Test Conditions 5.1 Temperature and Immersion Periods—Unless otherwise specified the test temperature and immersion period shall be as indicated in Table 1, depending upon the anticipated service conditions: 5.1.1 When the temperature of the testing room is other than the standard 23 6 2°C (73 6 4°F) the temperature of test shall be reported. 5.1.2 The choice of the immersion period will depend upon the nature of the vulcanizate, the test temperature, and the liquid to be used. To obtain information on the rate of deterioration it is necessary to make determinations after several immersion periods. The tolerance for any immersion period shall be 615 min or 61 % of the immersion period, whichever is greater. 5.2 Illumination— Immersion tests shall be made in the absence of direct light. 6. Standard Test Liquids 6.1 For test purposes, it is usually desirable to use the liquid that will come into contact with the vulcanizate in service. For comparative tests with liquids of unknown or doubtful com- position, samples of liquid from the same container or ship- ment shall be used. Many commercial products, particularly those of petroleum origin, are subject to sufficient variation that it is not practical to use them for test liquids. It is then advisable to use a standard test liquid, such as described in 6.1.1 and 6.1.2, covering the range of properties that may be encountered in the particular service. 6.1.1 ASTM and IRM Oils—The test shall be conducted in one of the petroleum-base ASTM or IRM oils (Note 1) specified in Table 2 that has its aniline point nearest that of the oil with which the vulcanizate is expected to come in contact in service except as indicated in 6.1.3. NOTE 1—The aniline point of a petroleum oil appears to characterize the swelling action of that oil on rubber vulcanizates. In general, the lower the aniline point, the more severe the swelling action by the oil. The oils specified in Table 2 cover a range of aniline points commonly found in lubricating oils. 6.1.2 ASTM Reference Fuels—When gasolines or diesel fuels are to be encountered in service, the test shall be conducted in one of the ASTM reference fuels (Note 2) specified in Table 3, except as indicated in 6.1.3. NOTE 2—The ASTM reference fuels in Table 3 have been selected to provide the maximum and minimum swelling effects produced by commercial gasolines. Reference Fuel A has a mild action on rubber vulcanizates and produces results of the same order as low swelling gasolines of the highly paraffinic, straight run type. Reference Fuels B, C, and D simulate the swelling behavior of the majority of commercial gasolines, with Reference Fuel C producing the highest swelling which is typical of highly aromatic premium grades of automotive gasoline. 7 Annual Book of ASTM Standards, Vol 05.02. 8 Annual Book of ASTM Standards, Vol 14.02. 9 Available from Society of Automotive Engineers (SAE), 400 Commonwealth Drive, Warrendale, PA 15096. 10 Reference Fuels A, B, C, D, and E are available from Phillips Petroleum Co., Customer Service Center, P.O. Box 968, Borger, TX 79007: Phone: 1 (800) 858-4327; FAX: 1 (806) 275-3771. TABLE 1 Test Temperatures and Immersion Periods Temperature in °C (°F) ImmersionPeriod, h −75 6 2 (−103 6 4) 85 6 2 (185 6 4) 22 −55 6 2 (−67 6 4) 100 6 2 (212 6 4) 46 −40 6 2 (−40 6 4) 125 6 2 (257 6 4) 70 −25 6 2 (−13 6 4) 150 6 2 (302 6 4) 166 −10 6 2 (14 6 4) 175 6 2 (347 6 4) 670 0 6 2 (32 6 4) 200 6 2 (392 6 4) 1006 23 6 2 (73 6 4) 225 6 2 (437 6 4) 2998 50 6 2 (122 6 4) 250 6 2 (482 6 4) 4990 70 6 2 (158 6 4) D 471 2 Reference Fuel F (diesel fuel) swells rubber vulcanizates to a lesser extent than Reference Fuel B. Reference Fuels G, H, and I are fuel-alcohol blends (gasohol), which have a stronger swelling action than the corre- sponding fuel alone, where blends with methanol are more severe than blends with ethanol. Reference Fuel K, a methanol-rich blend, has a substantially weaker swelling action than that of the fuel used to prepare the blend. Reference Fuels I and K are also referred to as M15 and M85, respectively. 6.1.3 Service Liquids— Some commercial oils, fuels and other service liquids (see Table 4) are either non-petroleum or are compounded from special petroleum hydrocarbon fractions or mixtures of petroleum hydrocarbon fractions and other ingredients resulting in materials having properties beyond the range of the reference fluids listed in Table 2 and Table 3. Immersion tests of rubber vulcanizates that are to come into contact with such fluids should be made in the actual service liquid. 6.1.4 Water—Since the purity of water varies throughout the world, all water immersion tests are to be conducted in distilled or deionized water. 7. Preparation of Specimen 7.1 Except as otherwise specified in the applicable specifi- cations, specimens shall be prepared in accordance with the requirements of Practices D 3182 and D 3183. 8. Apparatus 8.1 For non-volatile liquids, a glass test tube, having an outside diameter of 38 mm (1.5 in.) and an overall length of 300 mm (12 in.) fitted loosely with a stopper (see 8.2.1) shall be used.11 Glass beads shall be used in the liquid as a bumper and to separate the specimens. 8.2 For volatile liquids, the test tube described in 8.1 shall be tightly fitted with a stopper (see 8.2.1) and a reflux condenser. An air-cooled reflux condenser shall be used for ASTM Oils No. 112 ,13 and No. 5 and for IRM 90212 ,13 and 11 Test tubes available under Part No. LGB24 and LGB24C (case of 30) from Edwin H. Benz Co. Inc., 73T Maplehurst Ave., Providence, RI 02908 or under Part No. LG226 from Precision Scientific, 2777 Washington Blvd., Bellwood, IL 60104, have been found suitable for this purpose. 12 Information about ASTM Oil No. 1 is included in Research Report RR: D11-1004 and information about IRM 902 and IRM 903 in Research Report RR: D11-1069. Both reports are available from ASTM Headquarters. TABLE 2 Specifications and Typical Properties of ASTM and IRM Reference Oils Property ASTM Oil No. 1 ASTM Oil No. 5 IRM 902 IRM 903 ASTM Method Specified Properties: Aniline Point, °C (°F) 124 6 1 (255 6 2) 115 6 1 (2396 2) 93 6 3 (199 6 5) 706 1 (158 6 2) D 611 Kinematic Viscosity (mm2/s [cSt]) 38°C (100°F) ... ... ... 31.9–34.1 D 445 99°C (210°F) 18.7–21.0 10.8–11.9 19.2–21.5 ... D 445 Gravity, API, 16°C (60°F) ... ... 19.0–21.0 21.0–23.0 D 287 Viscosity-Gravity Constant ... ... 0.860–0.870 0.875–0.885 D 2140 Flash Point COC, °C (°F) 243 (469) min 243 (469) min 240 (464) min 163 (325) min D 92 Naphthenics, CN(%) ... ... 35 min 40 min D 2140 Paraffinics, CP(%) ... ... 50 max 45 max D 2140 Typical Properties: Pour Point, °C (°F) ... −15 (5) −12 (10) −31 (−24) D 97 ASTM Color ... L 1.0 L 2.5 L 0.5 D 1500 Refractive Index ... 1.4808 1.5105 1.5026 D 1747 UV Absorbance, 260 nm ... ... 4.0 2.2 D 2008 Aromatics, CA(%) ... 4 12 14 D 2140 TABLE 3 ASTM Reference Fuels Fuel Type Composition, Volume % Reference Fuel A IsooctaneA, 100 Reference Fuel B IsooctaneA, 70; TolueneA, 30 Reference Fuel C IsooctaneA, 50; TolueneA, 50 Reference Fuel D IsooctaneA, 60; TolueneA, 40 Reference Fuel E TolueneA, 100 Reference Fuel F Diesel Fuel, Grade No. 2B, 100 Reference Fuel G Fuel D, 85; anhydrous denatured ethanolC, 15 Reference Fuel H Fuel C, 85; anhydrous denatured ethanolC, 15 Reference Fuel I Fuel C, 85; anhydrous methanol, 15 Reference Fuel K Fuel C, 15; anhydrous methanol, 85 AMotor Fuels, Section 1, Test Method D 2699 BSpecification D 975. CAnhydrous ethanol denatured with unleaded gasoline (CDA formula No. 20), available from Archer-Daniels-Midland, P.O. Box 1470, Decatur, IL 62525. TABLE 4 ASTM Service Liquids Liquid Composition Service Liquid 101A di-2 ethyl hexyl sebacate, 99.5 mass %; phenothiazine, 0.5 mass % Service Liquid 102B ASTM Oil No. 1, 95 mass %; hydrocarbon compound additiveC, 5 mass % (29.5–33.5 mass % sulfur, 1.5–2.0 mass% phosphorus, 0.7 mass % nitrogen) Service Liquid 103D tri-n-butyl phosphate, 100 mass % Service Liquid 104E ethylene glycolF, 50 volume %; distilled water, 50 volume % Service Liquid 105G ASTM Reference Oil TMC 1006 Service Liquid 106H ARM 200 (Aerospace Reference Material 200) AService liquid 101 is intended to simulate the swelling action of synthetic diester-type lubricating oils. BService liquid 102 approximates the swelling behavior of hydraulic oils. CThis hydrocarbon oil additive is available as Anglamol 99 from Lubrizol Corp., 29400 Lakeland Blvd., Wickliffe, OH 44092. Properties are as follows: Kinematic viscosity (mm2/s [cSt]) at 99°C (210°F) − 9.70 6 0.52 (Test Method D 445); Flash point COC °C (°F) − 45 (113) min (Test Method D 92); Density at 16°C (61°F) − 1.065 6 0.015 (Test Method D 1217). DService liquid 103 simulates phosphate ester-type aircraft hydraulic oils. EService liquid 104 approximates the swelling behavior of automotive engine coolant. FEthylene glycol, reagent grade, shall be used. GService Liquid 105 is an API SJ/ILSAC GF-2 SAE 5W-30 reference engine oil meeting the requirements of ASTM D 4485 and SAE J 300. It is available from ASTM Test Monitoring Center, 6555 Penn Avenue, Pittsburgh, PA 15206–4489. Phone (412) 365–1000, Fax (412) 365–1047. HService Liquid 106 is intended to eventually replace Service Liquid 101 which is no longer readily available for purchase as a mixture. ARM 200 is available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096. D 471 3 IRM 90312,13 at test temperatures of 125°C (257°F) or more. This condenser shall be a glass tube, approximately 500 mm (20 in.) or longer, in length and 15 mm (0.6 in.) in outside diameter, tightly fitted to the immersion tube by means of a stopper (see 8.2.1). The bottom of the condenser tube shall project about 12 mm (0.47 in.) below the stopper. A suitable (watercooled) reflux condenser shall be used for water or other low-boiling liquids. Glass beads shall be used as in 8.1. 8.2.1 The stopper shall not contaminate the test liquid. When in doubt, cover the stopper with aluminum foil. 8.3 Maintaining Test Temperatures—The apparatus and method chosen to maintain the specified temperature during immersion testing varies with test conditions, requirements, and circumstances. Water baths, appropriate temperature trans- fer oil baths, hot air ovens Note 3, or aging blocks14 may be used. NOTE 3—When hot air ovens are used, it should be noted that contamination with volatile components of the immersion liquid may occur. This can affect test results, when the same ovens are subsequently used for hot air aging. 8.3.1 The preferred method for above room temperatures is the use of aging blocks, since they have the widest temperature capability. 8.3.2 Ovens—Type IIB ovens specified in Test Method E 145 are satisfactory for use through 70°C. For higher temperatures, Type IIA ovens are necessary. 8.3.2.1 The interior size shall be as follows or of an equivalent volume: Interior size of air oven: min 300 by 300 by 300 mm (12 by 12 by 12 in.) max 900 by 900 by 1200 mm (36 by 36 by 48 in.) 8.3.2.2 Provision shall be made for placing immersion test tubes in the oven without touching each other or the sides of the aging chamber and allowing proper air circulation around them. 8.3.2.3 The heating medium for the aging chamber shall be air circulated within it at atmospheric pressure. 8.3.2.4 The source of heat is optional but shall be located in the air supply outside of the aging chamber proper. 8.3.2.5 A recording thermometer located in the upper cen- tral portion of the chamber near the center of the aging specimens shall be provided to record the actual aging tem- perature. 8.3.2.6 Automatic temperature control by means of thermo- static regulation shall be used. 8.3.2.7 The following special precautions shall be taken in order that accurate, uniform heating is obtained in all parts of the aging chamber: 8.3.2.8 The heated air shall be thoroughly circulated in the oven by means of mechanical agitation. When a motor-driven fan is used, the air must not come in contact with the fan motor brush discharge because of danger of ozone formation. 8.3.2.9 Baffles shall be used as required to prevent local overheating and dead spots. 8.3.2.10 The thermostatic control device shall be so located as to give accurate temperature control of the heating medium. The preferred location is adjacent to the recording thermom- eter. 8.3.2.11 An actual check shall be made by means of maximum reading thermometers placed in various parts of the oven to verify the uniformity of the heating. 9. Test Specimens—Change in Mass or Volume 9.1 The standard specimen shall be rectangular, having dimensions of 25 by 50 by 2.0 6 0.1 mm (1 by 2 by 0.08 6 0.004 in.). Specimens from commercial articles shall be the thickness of the material as received when they are less than 2 mm (0.08 in.); otherwise they should be reduced to a thickness of 2.0 6 0.1 mm (0.08 6 0.004