ASTM_D_3900_-_15.pdf

Designation:D390015Standard Test Methods forRubberDetermination of Ethylene Units in Ethylene-Propylene Copolymers(EPM)and in Ethylene-Propylene-Diene Terpolymers(EPDM)by Infrared Spectrometry1This standard is issued under the fixed designation D3900;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.1.Scope1.1 These test methods cover the determination of theproportion of ethylene and propylene units in ethylene-propylene copolymers(EPM)and ethylene-propylenedieneterpolymers(EPDM)over the range from 35 to 85 mass%ethylene.Four test methods are needed to encompass thevariety of commercial polymers that contain additives orpolymerized diene units that interfere with the various infraredpeaks.Except when interferences are present,all four testmethods should give similar results.The test methods appear inthe following order:1.1.1 Pressed Film Test Methods:SectionsTest Method AFor EPM and EPDM between 35 and 70mass%ethylene9 14Test Method BFor EPM and EPDM between 60 and 85mass%ethylene,except for ethylene/propylene/1,4-hexadiene terpolymers15 19Test Method CFor all EPM and EPDM polymers between 35and 85 mass%ethylene,using near infrared20 241.1.2 Cast Film Test Methods:Test Method DFor all EPM and EPDM polymers between 35and 85 mass%ethylene,except for ethylene/propylene/1,4-hexadiene terpolymers25 321.2 These test methods are not applicable to oil-extendedEPDM unless the oil is first removed in accordance with TestMethod D.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 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:2D297 Test Methods for Rubber ProductsChemical Analy-sisD3568 Test Methods for RubberEvaluation of EPDM(Ethylene Propylene Diene Terpolymers)Including Mix-tures With OilD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesE168 Practices for General Techniques of Infrared Quanti-tative Analysis(Withdrawn 2015)33.Summary of Test Methods3.1 Test Method APressed films are measured for theirinfrared absorbance ratios at 8.65/13.85 m(1156/722 cm1),and mass percent ethylene is read from a calibration obtainedfrom standard polymers.NOTE1Peak typically appears at the wavelength indicated,but peakmay shift slightly in its position.3.2 Test Method BThin pressed films are measured fortheir infrared absorbance ratios at or near 7.25/13.85 m(1379/722 cm1),and mass percent ethylene is read from acalibration obtained from standard polymers.3.3 Test Method CPressed films are measured for theirinfrared absorbance ratios at or near 8.65/2.35 m(1156/4255cm1)using near infrared,and mass percent ethylene is readfrom a calibration obtained from standard polymers.3.4 Test Method DUltra-thin cast films on a salt plate aremeasured for their infrared absorbance ratios at or near7.25/6.85 m(1379/1460 cm1),and mass percent ethylene isread from a calibration obtained from standard polymers.1These test methods are under the jurisdiction of ASTM Committee D11 onRubber and are the direct responsibility of Subcommittee D11.11 on ChemicalAnalysis.Current edition approved June 1,2015.Published July 2015.Originally approvedin 1980.Last previous edition approved in 2010 as D3900 05a(2010).DOI:10.1520/D3900-15.2For 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 4.Significance and Use4.1 These test methods can be used for determining whichEPDM polymers are evaluated in the different compounds inTest Methods D3568.4.2 Differences in ethylene sequence distribution causedifferences in crystallinity and green strength at the sameethylene content.Since these are important variables in EPMand EPDM processability and end-use properties,the ethylenecontent of the rubber should not be used as the sole measure-ment to determine the suitability of a particular rubber for anintended purpose.5.Interferences5.1 Ethylene/propylene/1,4-hexadiene EPDM has an inter-ference at the 7.25-m(1379-cm1)peak and should bemeasured by Test Method A or C.5.2 Various commercial polymers have interferences due toadditives and stabilizers that prevent o