1、Designation: D 6843 02 (Reapproved 2007)Standard Test Method forSilanes Used in Rubber Formulations(bis-(triethoxysilylpropyl)sulfanes): Characterization by GasChromatography (GC)1This standard is issued under the fixed designation D 6843; the number immediately following the designation indicates t
2、he 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the characterization of
3、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 i
4、ts 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:2D 4626 Practice for Calculation of Gas ChromatographicResponse Factors
5、E 355 Practice for Gas Chromatography Terms and Rela-tionships3. Terminology3.1 Definitions:3.1.1 PTESPropyltriethoxysilane CH3CH2CH2Si(OEt)33.1.2 Cl-PTESChloropropyltriethoxysilane Cl-CH2CH2CH2Si(OEt)34. Summary of Test Method4.1 In this test method, a sample of the silane is analyzed bygas chromat
6、ography in order to determine the amount ofvolatile components. From the peak areas in the chromato-gram, the percents by weight of volatiles are totaled anddesignated as the total volatile impurities or volatile by-products.5. Significance and Use5.1 The amount of volatile components reflects the i
7、mpuritylevel 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
8、Carrier Gas Flow Control, with splitter.6.1.4 Temperature Controls, for injector, detector and col-umn.6.2 Syringe,1mm3(L).6.3 Analytical Balance, accuracy 60.1 mg.6.4 Automatic Pipets, 0.2 to 1.0 cm3,5cm3.6.5 Sample Vials, approximately 15 cm3.7. Reagents7.1 Methanol, analytical grade (for cleaning
9、 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
10、(for detector).7.6 Air, suitable for chromatographic use, total hydrocar-bons #2 ppm, moisture #3 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 editi
11、on approved Nov. 1, 2007. Published January 2008. Originallyapproved in 2002. Last previous edition approved in 2002 as D 6843 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informat
12、ion, 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
13、 PA 19428-2959, United States.8. Procedure8.1 Set up the gas chromatograph using the followingexample parameters as a guide:Carrier gas He, linear velocity 20 to 50 cm/sSplit ratio 1:4 to 1:10Injectortemperature 250COventemperature Temperature program: for example,50C / 2 min6.5C/min260C / 15 minNot
14、eThe above parameters can be adjustedas appropriate to match the column characteristics.For example, a more narrow column can use a fasterprogram (such as 50C for 1 min. hold/15C/min.ramp/300C for 15 min hold).Detectortemperature 320CCombustion gassesH2, air as needed for FID8.2 Tare a sample vial (
15、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.NOTE 1Before injection, the sample may be diluted 1:5 with cyclo-hexane.8.6 Inject 0.5 mm3(L) of the nea
16、t 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 take
17、s 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 the GCindicates a ready condition.9. Calculation9.1 The amount of each volatile component is calculated asfollows:I 5AiAstdW32 W2!W22 W1! RRi 100 %# (1)where:I = weight per cent
18、 of component i in the testsample,Ai= peak area of component i,Astd= peak area of undecane3(internal standard),RRi= response factor of component i,(W3W2) = weight in g of undecane3(internal standard),and(W2W1) = weight in g of silane sample.9.2 All components with a retention time smaller or equal t
19、oCl-PTES are considered to be “volatile impurities” or “volatileby-products.” If the identity of a volatile component is notknown, the response factor of Cl-PTES will be applied.9.3 See Table 1.10. Report10.1 Report the following information:10.1.1 Identification of the sample, and10.1.2 Volatile im
20、purities to the nearest 0.1 weight %.TABLE 1 Volatile ComponentsComponentsRetention TimeminPeak AreaV*sResponseFactorInitial WeightgConcentrationwt %Ethanol 1.46 5774 2.52 0.42PTES 12.99 6660 2.28 0.44Unknown 16.79 859 2.70 0.07Cl-PTES 18.35 27 557 2.70 2.15Total volatiles 3.01Sample mass 5.2529Unde
21、cane (internal std.) 14.79 483 627 1.00 0.7335D 6843 02 (2007)2ANNEX(Mandatory Information)A1. DETERMINATION OF RESPONSE FACTORSA1.1 ScopeA1.1.1 Mass (weight) relative response factors convertmeasured peak areas into weight % of a component. Responsefactors should be determined for Ethanol, Propyltr
22、iethoxysi-lane (PTES) and Chloropropyltriethoxysilane (Cl-PTES).A1.2 Standard ComponentsA1.2.1 Ethanol, absolute.A1.2.2 Propyltriethoxysilane (PTES), purity 99 %A1.2.3 Chloropropyltriethoxysilane (Cl-PTES), purity99 %.A1.2.4 Cyclohexane, analytical grade.A1.2.5 Undecane,3(internal standard, this wil
23、l have a de-fined response factor Rstd= 1.00).A1.3 ProcedureA1.3.1 Weigh 0.1 to 0.2 cm3of each component to bedetermined to the nearest 0.1 mg into one 15 cm3weighingbottle.A1.3.2 Add approximately 5 cm3cyclohexane to the mix-ture.A1.3.3 Reweigh the bottle to the nearest 0.1 mg; the netweight of the
24、 mixture represents the sample mass, m.A1.3.4 Add approximately 1 cm3undecane, the internalstandard, to the mixture.A1.3.5 Reweigh the bottle to the nearest 0.1 mg.A1.3.6 Homogenize the contents of the bottle by shakinggently.A1.3.7 Inject 0.3 mm3(L) of the final mixture into the gaschromatograph.A1
25、.4 CalculationA1.4.1 The mass relative response factors are individuallycalculated as follows:RRmi5Wi AstdAi Wstd(A1.1)where:RRmi= mass relative response factor of component i,Wi= weight of component i,Ai= peak area of component i,FIG. 1 Peak ReportD 6843 02 (2007)3Wstd= weight of standard (undecane
26、),Astd= peak area standard, andi = analyte component.A1.4.2 See Table A1.1.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
27、 of any such patent rights, and the riskof infringement of such 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
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29、received a fair hearing you shouldmake your views known to the 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 copie
30、s) 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).TABLE A1.1 Mass Relative Response FactorsComponentsRetention TimeminPeak Areafrom integratorComponent WeightgTotal Sample WeightgCalculated RelativeResponse FactorRRiConcentrationwt %Ethanol 1.44 32 928 0.1358 2.52 2.484PTES 13.05 46 550 0.1741 2.28 3.184Cl-PTES 18.39 41 886 0.1850 2.70 3.383Cyclohexane 4.9729Sample weight 5.4678Undecane(internal std.)14.79 446 926 0.7321 1.00D 6843 02 (2007)4
