1、Designation: D 6843 02Standard 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 the year oforiginal
2、 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 silanesof the type
3、 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 ther
4、esponsibility 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:D 4626 Practice for Calculation of Gas ChromatographicResponse Factors2E 355 Practice for
5、 Gas Chromatography Terms and Rela-tionships33. 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 chromatography in order
6、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 impuritylevel in t
7、he 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
8、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 syringe).7.2 Und
9、ecane,4analytical 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).7.
10、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 gas He, linear velocity 20 to 50 cm/sSplit ratio 1:4 to 1:10Injectortemperature 250C1This test met
11、hod 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 Dec. 10, 2002. Published January 2003. Originallyapproved in 2002. Last previous edition approved in 2002 as D 6843 02.
12、2Annual Book of ASTM Standards, Vol 05.02.3Annual Book of ASTM Standards, Vol 03.06.4Similar 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, Wes
13、t Conshohocken, PA 19428-2959, United States.Oventemperature Temperature program: for ex-ample,50C / 2 min6.5 C / min260C / 15 minNoteThe above parameterscan be adjusted as appropriateto match the column character-istics. For example, a more nar-row column can use a fasterprogram (such as 50C for 1m
14、in. hold/15C/min. ramp/300Cfor 15 min hold).Detectortemperature 320CCombustiongasses H2, 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 cm3undecane4(internal standard) and weighagain (W3).8.5 Homogenize t
15、he 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 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 Th
16、e 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 the GCindicates a ready condition.9. Calcul
17、ation9.1 The amount of each volatile component is calculated asfollows:I 5AiAstdW32 W2!W22 W1! RRi 100 %# (1)where:I = weight per cent of component i in the testsample,Ai= peak area of component i,Astd= peak area of undecane4(internal standard),RRi= response factor of component i,(W3W2) = weight in
18、g of undecane4(internal standard),and(W2W1) = weight in g of silane sample.9.2 All components with a retention time smaller or equal toCl-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
19、 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 impurities to the nearest 0.1 weight %.D6843022ANNEX(Mandatory Information)A1. DETERMINATION OF RESPONSE FACTORSA1.1 ScopeA1.1.1 Mass (weight) relative response factors
20、 convertmeasured peak areas into weight % of a component. Responsefactors should be determined for Ethanol, Propyltriethoxysi-lane (PTES) and Chloropropyltriethoxysilane (Cl-PTES).A1.2 Standard ComponentsA1.2.1 Ethanol, absolute.A1.2.2 Propyltriethoxysilane (PTES), purity 99 %A1.2.3 Chloropropyltrie
21、thoxysilane (Cl-PTES), purity99 %.A1.2.4 Cyclohexane, analytical grade.A1.2.5 Undecane,4(internal standard, this will have a de-fined response factor Rstd= 1.00).TABLE 1 Volatile ComponentsComponentsRetention TimeminPeak AreaV*sResponseFactorInitial WeightgConcentrationwt %Ethanol 1.46 5774 2.52 0.4
22、2PTES 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 5.2529Undecane (internal std.) 14.79 483 627 1.00 0.7335FIG. 1 Peak ReportD6843023A1.3 ProcedureA1.3.1 Weigh 0.1 to 0.2 cm3of each component to bedetermined to the nearest 0.1 mg into o
23、ne 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 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
24、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.A1.4 CalculationA1.4.1 The mass relative response factors are individuallycalculated as follows:RRmi5Wi AstdAi Wstd(A1.1)where:RRmi= mass relative resp
25、onse factor of component i,Wi= weight of component i,Ai= peak area of component i,Wstd= weight of standard (undecane),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
26、 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 rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible techni
27、cal 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 additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideratio
28、n at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not 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 Harb
29、or 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.
30、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 1.00D6843024
