ASTM_D_6843_-_10_2015.pdf

Designation:D684310(Reapproved 2015)Standard Test Method forSilanes Used in Rubber Formulations(bis-(triethoxysilylpropyl)sulfanes):Characterization by GasChromatography(GC)1This standard is issued under the fixed designation D6843;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 This test method covers the characterization of silanesof the type bis-(triethoxysilylpropyl)sulfanes by gas chroma-tography.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:2D4626 Practice for Calculation of Gas ChromatographicResponse FactorsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE355 Practice for Gas Chromatography Terms and Relation-shipsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions:3.1.1 PTESPropyltriethoxysilane CH3CH2CH2Si(OEt)33.1.2 Cl-PTESChloropropyltriethoxysilaneCl-CH2CH2CH2Si(OEt)34.Summary of Test Method4.1 In this test method,a sample of the silane is analyzed bygas chromatography in order to determine the amount ofvolatilecomponents.Fromthepeakareasinthechromatogram,the percents by weight of volatiles are totaledand designated as the total volatile impurities or volatileby-products.5.Significance and Use5.1 The amount of volatile components reflects the impuritylevel in the product,and as a consequence,its behavior in arubber mixture.6.Apparatus6.1 Gas Chromatograph,equipped with:6.1.1 Flame Ionization Detector(FID).6.1.2 Capillary Column,typical is 30 m length,0.25 to 0.53mm internal diameter,fused silica,0.1 to 1.0 m film thickness.6.1.3 Carrier Gas Flow Control,with splitter.6.1.4 Temperature Controls,for injector,detector and col-umn.6.2 Syringe,1 mm3(L).6.3 Analytical Balance,accuracy 60.1 mg.6.4 Automatic Pipets,0.2 to 1.0 cm3,5 cm3.6.5 Sample Vials,approximately 15 cm3.7.Reagents7.1 Methanol,analytical grade(for cleaning syringe).7.2 Undecane,3analytical grade(used as internal standard).7.3 Optional:Cyclohexane,analytical grade(used to dilutethe sample).7.4 Helium,minimum 99.99%purity,suitable for chro-matographic use,dried(carrier gas).7.5 Hydrogen Gas,minimum 99.99%purity,total hydro-carbons 1 ppm(for detector).1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.20 on Compounding Materialsand Procedures.Current edition approved June 1,2015.Published September 2015.Originallyapproved in 2002.Last previous edition approved in 2010 as D6843 10.DOI:10.1520/D6843-10R15.2For 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.3Similar hydrocarbons like decane,analytical grade,can be used in place ofundecane,as long as they do not interfere with peaks from the sample.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.6 Air,suitable for chromatographic use,total hydrocar-bons 2 ppm,moisture 3 ppm(for detector).8.Procedure8.1 Set up the gas chromatograph using the followingexample parameters as a guide:Carrier gasHe,linear velocity 20 to 50 cm/sSplit ratio1:4 to 1:10Injectortemperature250COventemperatureTemperature program:for example,50C/2 min6.5 C/min260C/15 minNOTE1The above parameters can beadjustedas appropriate to match the column charac-teristics.For example,a more narrow column can usea fasterprogram(such as 50C for 1 min.hold/15C/min.ramp/300C for 15 min hold).Detectortemperature320CCombustion gas-sesH2,air as needed for FID8.2 Tare a sample vial(W1).8.3 Weigh 5 cm3of Bis-(triethoxysilylpropyl)sulfanes intothe tared sample vial(W2).8.4 Add 1 cm3undecane3(internal standard)and weighagain(W3).8.5 Homogenize the solution by shaking gently.NOTE1Before injection,the sample may be diluted 1:5 withcyclohexane.8.6 Inject 0.5 mm3(L)of the neat sample or 1.0 mm3(L)of the diluted sample into the gas chromatograph and start themeasurement process.8.7 Clean the syringe immediately with methanol and dry.8.8 The measurement is finished when the base line isreached after a broad peak(indicative of the trisulfane species).Typically,a run takes less than 30 min.8.9 Allow the oven to cool down to the start temperature.The next measurement may be started as soon as th