1、Designation: D6843 10 (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
2、 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 sil
3、anesof 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
4、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
5、 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(
6、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 to determine the amount ofvolatile components. From the peak areas in thechromatogram, the percents by weight of volati
7、les 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 F
8、lame 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, 1mm3(L).6.3 Analytical
9、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 Undecane,3analytical grade (used as internal standard).7.3 Optional: Cyclohexane, analytical grade (used to dilutethe sample
10、).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
11、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
12、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.
13、Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States17.6 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
14、a guide:Carrier gas He, linear velocity 20 to 50 cm/sSplit ratio 1:4 to 1:10Injectortemperature250COventemperatureTemperature program: for example,50C / 2 min6.5C/min260C / 15 minNOTE 1The above parameters can beadjustedas appropriate to match the column charac-teristics.For example, a more narrow c
15、olumn 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(intern
16、al standard) and weighagain (W3).8.5 Homogenize the solution by shaking gently.NOTE 1Before 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 s
17、yringe 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
18、 as the GCindicates a ready condition.9. Calculation9.1 The amount of each volatile component is calculated asfollows:I 5AiAstdW32 W2!W22 W1!RRi100 %# (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= respo
19、nse 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 toCl-PTES are considered to be “volatile impurities” or “volatileby-products.” If the identity of a volatile component is
20、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 impurities to the nearest 0.1 weight %.11. Precision and Bias411.1 The precision of this test method is based on aninterlab
21、oratory 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,
22、Practice 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
23、testresults 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
24、 “R” valuefor that material; “R” is the interval representing the critical4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D11-1103.TABLE 1 Volatile ComponentsComponentsRetention TimeminPeak AreaV*sResponseFactorInitial WeightgCo
25、ncentrationwt %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 5.2529Undecane (internal std.) 14.79 483 627 1.00 0.7335D6843 10 (2015)2difference between two test results for the same material,obtained by di
26、fferent operators using different equipment indifferent laboratories.11.1.2.1 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
27、 or11.1.2 would 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-
28、tistical examination 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; si
29、lanes; volatile 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 10 (2
30、015)3ANNEX(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, Propyltriethoxysi-lane (PTES) and Chloropropyltriethoxysilane (Cl-
31、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 will have a de-fined response factor Rstd= 1.00).A1.3 Procedu
32、reA1.3.1 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 mixture represents the sample mass, m.A1.3.4 Add approxim
33、ately 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.A1.4 CalculationA1.4.1 The mass relative response factors ar
34、e individuallycalculated as follows:RRmi5WiAstdAiWstd(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.D6843 10 (2015)4ASTM
35、 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 of any such patent rights, and the riskof infringement of such rights, are ent
36、irely 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 are invited either for revision of this standard or for additional standardsan
37、d should be addressed to ASTM International 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 o
38、n 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 copies) of this standard may be obtained by contacting ASTM at the aboveaddress or a
39、t 610-832-9585 (phone), 610-832-9555 (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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ A1.1 Mass Relativ
40、e 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 10 (2015)5
