ASTM_D_454_-_04_2015.pdf

Designation:D45404(Reapproved 2015)Standard Test Method forRubber Deterioration by Heat and Air Pressure1This standard is issued under the fixed designation D454;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method covers a procedure to determine theinfluence of elevated temperature and air pressure on thephysical properties of vulcanized rubber.The results of this testmay not give an exact correlation with service performancesince performance conditions vary widely.The test may,however,be used to evaluate rubber compounds on a labora-tory comparison basis.It will be most applicable to perfor-mance under conditions of increased temperature and airpressure.NOTE1For evaluating rubber vulcanizates under less severe condi-tions that more nearly approach natural aging,the use of Test MethodsD573 and D865 is recommended.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 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D15 Method of Compound and Sample Preparation forPhysical Testing of Rubber Products(Withdrawn 1975)3D412 Test Methods for Vulcanized Rubber and Thermoplas-tic ElastomersTensionD572 Test Method for RubberDeterioration by Heat andOxygenD573 Test Method for RubberDeterioration in an AirOvenD865 Test Method for RubberDeterioration by Heating inAir(Test Tube Enclosure)D3182 Practice for RubberMaterials,Equipment,and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized SheetsD3183 Practice for RubberPreparation of Pieces for TestPurposes from ProductsD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries3.Summary of Test Method3.1 Specimens of vulcanized rubber are exposed to thedeteriorating influence of air at specified elevated temperatureand pressure for known periods of time,after which theirphysical properties are determined.These are compared withthe properties determined on the original specimens and thechanges noted.3.2 Unless otherwise specified,the determination of thephysical properties shall be carried out in accordance with TestMethods D412.3.3 Except as may be otherwise specified in this testmethod,the requirements of Practices D3182 and D3183 shallbe complied with and are made part of this test method.3.4 In case of conflict between the provisions of this testmethod and those of detailed specifications or test methods fora particular material,the latter shall take precedence.4.Significance and Use4.1 Rubber and rubber products must resist the deteriorationof physical properties with time caused by oxidative andthermal aging.This test method allows these performanceproperties to be determined under the accelerated conditions ofhigh air pressure and at elevated temperatures.4.2 Refer to the Annex in Test Method D573 for importantinformation on standard compounds used for precision testingfor accelerated test aging evaluation.5.Apparatus5.1 Air-Pressure Chamber,consisting of a metal vesseldesigned to maintain an internal atmosphere of air under1This 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 July 1,2015.Published October 2015.Originallyapproved in 1952.Last previous edition approved in 2010 as D454 04(2010).DOI:10.1520/D0454-04R15.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 known pressure,with provisions for placing rubber specimenswithin it and subjecting them to controlled uniform tempera-ture.The equipment shall conform to the following require-ments:5.1.1 The size and shape of the chamber shall be optional,but shall be such that the specimens may be suspended thereinvertically without undue crowding and without touching eachother or the sides of the chamber.5.1.2 The operating temperature shall be 125 6 1C(257 61.8F)determined as described in 5.1.5.The temperature shallbe automatically controlled by means of ther