1、Designation: D6843 10Standard 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 a
2、doption 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 bi
3、s-(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 theresp
4、onsibility 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
5、of the Terms Precision and Bias inASTM Test MethodsE355 Practice for Gas Chromatography Terms and Rela-tionshipsE691 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-PTES
6、Chloropropyltriethoxysilane Cl-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 ofvolatile components. From the peak areas in the chromato-gram, the percents by weight of volatiles are totaled
7、anddesignated as the total volatile impurities or volatile by-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
8、 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,1mm3(L).6.3 Analytical Balance, accurac
9、y 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 Undecane,3analytical grade (used as internal standard).7.3 Optional: Cyclohexane, analytical grade (used to dilutethe sample).7.4 Helium, mi
10、nimum 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 Compo
11、unding Materialsand Procedures.Current edition approved June 1, 2010. Published July 2010. Originally approvedin 2002. Last previous edition approved in 2007 as D6843 02 (2007). DOI:10.1520/D6843-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service
12、 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.1Copyright ASTM
13、International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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:Carri
14、er 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 minNoteThe above parameters can be adjustedas appropriate to match the column characteristics.For example, a more narrow column can use
15、 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 (W1).8.3 Weigh 5 cm3of Bis-(triethoxysilylpropyl)sulfanes intothe tared sample vial (W2).8.4 Add 1 cm3undecane3(internal standard)
16、 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 neat sample or 1.0 mm3(L)of the diluted sample into the gas chromatograph and start themeasurement process.8.7 Clean the syringe imm
17、ediately 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 the GC
18、indicates 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 of component i in the testsample,Ai= peak area of component i,Astd= peak area of undecane3(internal standard),RRi= response fact
19、or 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 toCl-PTES are considered to be “volatile impurities” or “volatileby-products.” If the identity of a volatile component is notknown
20、, 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 impurities to the nearest 0.1 weight %.11. Precision and Bias411.1 The precision of this test method is based on aninterlaboratory
21、study conducted in 2008. Nine laboratoriesparticipated in this study. Each of the labs reported fourreplicate test results for the sum of volatile components on asingle material. Every “test result” reported represents anindividual determination. Except for the use of only a singlematerial, Practice
22、 E691 was followed for the design andanalysis of the data.11.1.1 Repeatability limit (r)Two test results obtainedwithin one laboratory shall be judged not equivalent if theydiffer by more than the “r” value for that material; “r”istheinterval representing the critical difference between two testresu
23、lts for the same material, obtained by the same operatorusing the same equipment on the same day in the samelaboratory.11.1.1.1 Repeatability limits are listed in Table 1 and Table2.11.1.2 Reproducibility limit (R)Two test results shall bejudged not equivalent if they differ by more than the “R” val
24、uefor that material; “R” is the interval representing the criticaldifference between two test results for the same material,obtained by different operators using different equipment indifferent laboratories.4Supporting data have been filed at ASTM International Headquarters and maybe obtained by req
25、uesting Research Report RR:D11-1103.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 5.2529Undec
26、ane (internal std.) 14.79 483 627 1.00 0.7335D6843 10211.1.2.1 Reproducibility limits are listed in Table 1 andTable 2.11.1.3 The above terms (repeatability limit and reproduc-ibility limit) are used as specified in Practice E177.11.1.4 Any judgment in accordance with statement 11.1.1 or11.1.2 would
27、 have an approximate 95 % probability of beingcorrect.11.2 BiasAt the time of the study, there was no acceptedreference material utilized for determining the bias for this testmethod, therefore no statement on bias is being made.11.3 The precision statement was determined through sta-tistical examin
28、ation of 36 results, from nine laboratories, onone material. Due to the small number of participating labs, nooutliers were removed. This material was described as follows:Material A is a commercially available bis-(triethoxysilylpropyl)tetra sulfane.12. Keywords12.1 organisilanes; silanes; volatile
29、 componentsFIG. 1 Peak ReportTABLE 2 Volatile Impurities (wt %)Material AverageARepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitx SxSrSRrRA 1.12 0.09 0.04 0.10 0.11 0.27AThe average of the laboratories calculated averages.D6843 103ANNEX(Mandatory I
30、nformation)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, Propyltriethoxysi-lane (PTES) and Chloropropyltriethoxysilane (Cl-PTES).A1.2 Standard Co
31、mponentsA1.2.1 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 will have a de-fined response factor Rstd= 1.00).A1.3 ProcedureA1.3.1 Weigh 0.1 to
32、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 mixture represents the sample mass, m.A1.3.4 Add approximately 1 cm3undecane, t
33、he 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.A1.4 CalculationA1.4.1 The mass relative response factors are individuallycalculat
34、ed 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,Wstd= weight of standard (undecane),Astd= peak area standard, andi = analyte component.A1.4.2 See Table A1.1.ASTM International takes no position res
35、pecting 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 of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This
36、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 are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Intern
37、ational Headquarters. Your comments will receive careful consideration 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 be
38、low.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 copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555
39、 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).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 1.00D6843 104
