1、Designation: D 3137 81 (Reapproved 2007)Standard Test Method forRubber PropertyHydrolytic Stability1This standard is issued under the fixed designation D 3137; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. A number in parentheses indicates the year of last reapproval. Asuperscript 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.1. Scope1.1 This test method covers the determination of th
3、e abilityof rubber to withstand the environmental effects of highhumidity. This is accomplished by examination of the materialafter removal from the moisture-laden environment. It isdesigned for testing specimens of rubber materials cut fromstandard sheets prepared in accordance with Practice D 3182
4、.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish ap
5、pro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. (For specificprecautionary statements, see Note 1.)2. Referenced Documents2.1 ASTM Standards:2D 412 Test Methods for Vulcanized Rubber and Thermo-plastic ElastomersTensionD 573 Test Method
6、 for RubberDeterioration in an AirOvenD 3040 Practice for Preparing Precision Statements forStandards Related to Rubber and Rubber Testing3D 3182 Practice for RubberMaterials, Equipment, andProcedures for Mixing Standard Compounds and Prepar-ing Standard Vulcanized Sheets3. Summary of Test Method3.1
7、 Test specimens are exposed to the influence of humidenvironments under definite conditions of temperature, humid-ity, and time for the purpose of measuring the resultinghydrolytic degradation by noting the change in tensile strengthafter exposure over distilled water.4. Significance and Use4.1 Rubb
8、er and rubber products for certain applicationsmust withstand the environmental effect of high humidity andresist the deterioration of physical properties under theseconditions with time. This test method allows performanceproperties to be determined under the accelerated conditions ofhigh humidity
9、and elevated temperature.4.2 In view of climatic variations in service conditions, thismethod may not give results correlating exactly with serviceperformance. However, the test method yields comparativedata on which to base judgment as to service quality and it isuseful in research and development
10、work.4.3 This test method is not applicable to coated fabrics; itsuse for materials other than rubber has not been established.5. Test Conditions5.1 TemperatureThe test temperature shall be 85 6 1C(185 6 2F).5.2 Exposure PeriodThe exposure period shall be 96 6 1h.5.3 Conditioning PeriodAfter the spe
11、cified exposure pe-riod, the specimens shall be conditioned on a flat surface for 16to96hat506 5 % relative humidity and 23 6 2C (73.4 63.6F).6. Procedure6.1 Original Tensile StrengthCut three ASTM dumbbellor ring specimens and condition for at least3hat236 2C(73.4 6 3.6F) prior to testing. Determin
12、e the original tensilestrength in accordance with Test Methods D 412.6.2 Deteriorated Tensile StrengthCut three specimensfrom the same rubber sheet from which specimens were cut forthe original tensile strength. Measure the thickness of eachspecimen and suspend the specimens in a container approxi-m
13、ately 1 dm3(1 qt) in volume and at least 170 mm (6.7 in.) inheight, containing 100 cm3of distilled water. Suspend thespecimens on noncorrosive metal hooks, soldered to thebottom of the container cap or on a glass “tree” placed in thecontainer, so that the specimens do not contact the container or1Th
14、is test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.15 on Degradation Tests.Current edition approved March 1, 2007. Published May 2007. Originallyapproved in 1972. Last previous edition approved in 2001 as D 3137 81 (2001).2For
15、 referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive,
16、PO Box C700, West Conshohocken, PA 19428-2959, United States.each other. Cap the container loosely and place the container ina circulating air oven (see Test Method D 573) according to therequired test conditions (see 5.1 and 5.2). After 15 min, openthe oven briefly and secure the container cap tigh
17、tly. At the endof the required exposure period, remove the container from theoven and loosen the cap (see Note 1). When the container hascooled to approximately room temperature, remove and con-dition the specimens (see 5.3). After the conditioning period,determine the tensile strength in accordance
18、 with Test MethodsD 412, using the original unexposed thickness or cross-sectional area.NOTE 1The cap of the container should not be secured tightly prior toplacing the container in a circulating air oven at elevated temperature.Such a procedure could result in a potentially hazardous conditioninvol
19、ving a pressurized container. Similarly, the container cap should beloosened upon removal from the oven to prevent the occurrence of apartial vacuum in the sealed container.NOTE 2It should be recognized that the change in tensile strength ofa rubber that has been exposed to the conditions of this te
20、st may be due,in part, or totally, to the effects of the elevated temperature rather than tothe effects of humidity. To aid in distinguishing between the two effects,it is recommended that in addition to testing specimens of rubber bymeans of this method, specimens also be tested for change in tensi
21、lestrength in accordance with Test Method D 573 for 96 6 1hat856 1C(185 6 2F).NOTE 3In the event that a significant loss in tensile strength is notedafter the 96 6 1-h exposure over water (a loss not attributed to the effectsof heat alone), the rubber may be considered to be hydrolytically unstableu
22、nder these conditions. In cases where it is difficult to make this judgment,or whether it is desired to perform in-depth studies of the rates ofhydrolysis, the test over water at 85 6 1C (185 6 2F) may be performedfor longer exposure periods. Suggested exposure intervals are 168 6 1,240 6 1, and 336
23、 6 1 h. For in-depth studies of materials having poorresistance to hydrolysis under the standard test conditions (see Section 5),a lower test temperature such as 70 6 1C (158 6 2F) may be used.6.3 Take the median of the values for three specimens as thecharacteristic of the piece of rubber tested wi
24、th the exception ofthe following conditions, in which case use the median of thevalues for five specimens:6.3.1 If one or more values do not meet the specifiedrequirements when tested for compliance with specifications,or6.3.2 If referee tests are being made.7. Calculation7.1 Calculate the percentag
25、e change in tensile strength asfollows:Percent change in tensile strength 5 T 2 T0!/T0# 3 100 (1)where:T0= original tensile strength of specimens, andT = tensile strength after exposure.8. Report8.1 The report shall include the following:8.1.1 Results calculated in accordance with Section 6,8.1.2 Al
26、l observed and recorded data on which the calcula-tions are based,8.1.3 Time of exposure,8.1.4 Date of preparation of the rubber, if known,8.1.5 Date of test, and8.1.6 Type and dimensions of specimens used.9. Precision and Bias9.1 This precision statement was prepared in accordancewith statistical a
27、nd other testing terminology and conceptspresented in Practice D 3040.9.2 The precision of this test method was calculated fromthe precision statement of Test Methods D 412 for the tensilestrength measurement of rubber-like materials. These precisiondata are based on tests conducted exclusively with
28、 vulcanizedsheets prepared by the National Bureau of Standards by 69laboratories on 9 materials. A “test result” is the mean valueobtained from the testing of 3 dumbbell specimens.9.3 This test method measures the percentage of change intensile strength of a rubber-like material after exposure for 9
29、6h to a hydrolytic environment. The best estimate of precisionfor this test method is derived from twice that of the variancemeasured for the tensile strength in accordance with TestMethods D 412.9.4 The calculated laboratory quality control (LQC) preci-sions for this test method are shown as follow
30、s:Property, % change intensile strength Units, %Range of Value,0to100%Within Laboratory Among LaboratoryS CV LSD S CV LSD2.1 0.042 5.9 4.2 0.084 11.99.5 The LQC precision values for S (%) given are equiva-lent to “repeatability” for within-laboratory testing and to“reproducibility” for among-laborat
31、ory testing.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such
32、 rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additi
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34、ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 3137 81 (2007)2
