1、Designation: D 6741 01 (Reapproved 2006)Standard Test Methods forSilanes Used in Rubber Formulations(bis-(triethoxysilylpropyl)sulfanes): Sulfur Content1This standard is issued under the fixed designation D 6741; the number immediately following the designation indicates the year oforiginal adoption
2、 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 These test methods cover the determination of the sulfurcontent of silanes,
3、 or of admixtures of silane and carbon black,of the type bis-(triethoxysilylpropyl)sulfane. The following testmethods are included:Test Method A: Combustion in an Oxygen Flask and SubsequentTitration of SulfateTest Method B: High-Temperature Combustion with InfraredAbsorption Detection1.2 The values
4、 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 safe
5、ty and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent Water3. Significance and Use3.1 The sulfur content can be used to characterize a silane oran admixture of silane and carbon blac
6、k. It depends mainly onthe average length of the sulfur chain.Test Method A: Combustion in an Oxygen Flask andSubsequent Titration of Sulfate4. Summary of Test Method4.1 The weighed sample is burned in an oxygen atmo-sphere. The resulting sulfur dioxide and trioxide is absorbed inhydrogen peroxide s
7、olution, and the sulfate ions thus generatedare titrated with barium perchlorate solution employing Thorinindicator. Taking into account the known concentration of theperchlorate solution, the volume consumed, and the samplemass, the sulfur content of the sample can be calculated.5. Apparatus5.1 Ana
8、lytical Balance, accuracy 60.1 mg.5.2 Combustion Apparatus, according to Schoeniger, with750 cm3flask.5.3 Ultrasonic Bath.5.4 Automatic Titrator.5.5 Photoelectrical Detector, set at 550 nm.5.6 Volumetric Cylinder, 100 cm3.5.7 Volumetric Flask, 100 cm3.5.8 Volumetric Pipet,10cm3.5.9 Syringe, 0.5 cm3.
9、5.10 Titration Beakers.5.11 Magnetic Stirrer, with stirring rod.5.12 Filter Paper, for Schoeniger combustion (35 3 35 370 mm).5.13 Glass Tube, attached to a rubber hose.6. Reagents6.1 Purity of ReagentsReagent grade shall be used in alltests. Unless otherwise indicated, it is intended that all reage
10、ntsshall conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.3Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accu
11、racy ofthe determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Specification D 1193.6.3 2-propanol 99 %.6.4 Hydrogen Peroxide Solution, (5 %) as absorbing liquid.6.5 Barium Perchlorate Solution, 0.005 mol/dm3in2-propa
12、nol/water.1These test methods are under the jurisdiction of ASTM Committee D11 onRubber and are the direct responsibility of Subcommittee D11.20 on CompoundingMaterials and Procedures.Current edition approved Oct. 1, 2006. Published November 2006. Originallyapproved in 2001. Last previous edition ap
13、proved in 2001 as D 6741 01.2For 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.3Reagent Chemicals, American Chem
14、ical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Ph
15、armacopeial Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.6 Thorin Solution, 0.1 % in water (Thorin octahydrate).6.7 Sulfuric Acid, as a standard solution (1.000 6 0.002 gSO42-).6.8 Deionized
16、 Water.6.9 Oxygen.6.10 Sulfanilic Acid, (certified standard for elemental analy-sis).7. Preparation of ApparatusNOTE 1The flask shall not contain any residues from solvents. Purgewith compressed air if necessary.NOTE 2Check flask for damages. Do not use flasks having scratchesor cracks.NOTE 3Ignite
17、with safety shield lowered only.NOTE 4After combustion is finished, leave flask in the apparatus for5 min cool-down.7.1 Add 20 cm3of 5 % H2O2solution into the combustionflask by means of a volumetric cylinder.7.2 Add a magnetic stirring rod.7.3 Purge the flask for 1 min with oxygen gas. Do this bydi
18、recting a gentle stream from the glass tube towards thebottom of the flask.8. Procedure8.1 Preparation of Liquid Samples (Silanes):8.1.1 Place a non-densified cotton wool swab between theplatinum grids attached to the glass stopper. The spare placebetween the grids should be filled to23 .8.1.2 Attac
19、h the ignition strip in such way that it is incontact with the heating coil.8.1.3 Transfer the stopper onto the balance, add approxi-mately 60 mg of silane and record the mass to the nearest 0.1mg.8.2 Preparation of Solid Samples (Admixtures of CarbonBlack and Silane):8.2.1 Fold the special filter p
20、aper as to form a tunnel andtransfer it onto the balance.8.2.2 Add approximately 120 mg of the admixture andrecord the mass to the nearest 0.1 mg.8.2.3 Fold the paper, roll it together and insert it between theplatinum grids. Make sure the ignition strip is in contact withthe heating coil.8.3 Combus
21、tion:8.3.1 Insert the stopper including the sample into the flask.Turn the flask upside down and fix it inside the combustionapparatus.8.3.2 Lower the safety shield and start ignition by pushingthe button.8.3.3 After 5 min take the flask out of the apparatus and stirfor 30 min with a magnetic stirre
22、r.8.3.4 Rinse the platinum grids with approximately 20 cm3of deionized water, while holding it above the combustionflask.8.3.5 Transfer the liquid from the combustion flask to a 100cm3volumetric flask, rinse, and make up to the mark withdeionized water.8.4 Titration:8.4.1 Pipet 10 cm3from the volume
23、tric flask into thetitration beaker.8.4.2 Add 40 cm32-propanol and 0.1 cm3Thorin solution.NOTE 5It is important to respect the proportion of water/2-propanol(1:4).8.4.3 Degas in the ultrasonic bath for 5 min.8.4.4 Add barium perchlorate until the color changes fromyellow to pale rose. Preferably use
24、 an automatic titratorequipped with photoelectrical detector.8.5 Standardization of the Barium Perchlorate Solution:8.5.1 Pipet 10 cm3of sulfuric acid standard solution into atitration beaker and proceed as described in 8.4. Result = V0.NOTE 6Ion chromatography can be used as an alternative method f
25、orsulfate determination.9. Calibration9.1 Use sulfanilic acid as a standard for calibration. Carryout the test as described in Sections 7 and 8. The theoreticalsulfur content of sulfanilic acid is 18.5 %. If this value is notobtained within 60.2 % (absolute), check reagents and appa-ratus, glassware
26、, and calculation.10. Calculation10.1 Calculate the sulfur content in percentage, according tothe following equation:S 5V F 0.1603 Vtotalm Valiquot 100 (1)where:V = volume of barium perchlorate solution,F = factor of barium perchlorate solution F =10.41V0(determined using sulfuric acid standard solu
27、-tion),0.1603 = conversion factor from cm30.005 m bariumperchlorate solution to mg S,Vtotal= total volume of sulfate-containing solution(here: 100 cm3),Valiquot= aliquot part used for titration, cm3, andm = original sample mass, mg.Test Method B: High-Temperature Combustion withInfrared Absorption D
28、etection11. Summary of Test Method11.1 The specimen is burned in a tube furnace at a minimumoperating temperature of 1350C in a stream of oxygen tooxidize the sulfur. Moisture and particulates are removed fromthe gas by traps filled with anhydrous magnesium perchlorate.The gas stream is passed throu
29、gh a cell in which sulfur dioxideis measured by an infrared (IR) absorption detector. Sulfurdioxide absorbs IR energy at a precise wavelength within theIR spectrum. Energy is absorbed as the gas passes through thecell body in which the IR energy is being transmitted. Thus, atthe detector, less energ
30、y is received. All other IR energy iseliminated from reaching the detector by a precise wavelengthfilter. Thus, the absorption of IR energy can be attributed onlyto sulfur dioxide whose concentration is proportional to thechange in energy at the detector. One cell is used as both areference and a me
31、asurement chamber. Total sulfur as sulfurdioxide is detected on a continuous basis. This test method isD 6741 01 (2006)2empirical. Therefore, the apparatus shall be calibrated by theuse of a standard reference material.11.2 This test method is for use with commercially availablesulfur analyzers equi
32、pped to carry out the preceding operationsautomatically and shall be calibrated using a standard referencematerial (sulfanilic acid) containing sulfur in the same order ofmagnitude as the samples to be analyzed.12. Apparatus12.1 Measurement Apparatus, equipped to automaticallycombust the specimen.12
33、.2 Combustion Tube, made of mullite, porcelain, or zir-con, approximately 40 to 45 mm inside diameter with a 3-mmthick wall, at least 450 mm long with provisions for routing thegases produced by combustion through the infrared cell.12.3 Boat Puller, rod of a heat-resistant material with a bentor dis
34、k end to insert and remove boats from the combustiontube.13. Reagents13.1 Purity of Reagentssee 6.1.13.2 Magnesium Perchlorate.14. Preparation of Apparatus14.1 Assemble the apparatus according to the manufactur-ers instructions. Make a minimum of two determinations tocondition the system prior to ca
35、librating the system.15. Calibration15.1 Carry out four tests with different amounts of sulfanilicacid. Choose the sample mass such that it includes the expectedamount of sulfur present in the silane sample.15.2 Follow the instructions of the manufacturer.16. Procedure16.1 Stabilize and calibrate th
36、e analyzer (see 15.1 and 15.2).16.2 Raise the furnace temperature as recommended by themanufacturer to at least 1350C. Weigh the specimen to thenearest 0.1 mg into a combustion boat and use a boat puller toposition the specimen in the hot zone of the furnace for at least2 min, or until completely co
37、mbusted.NOTE 7The analytical cycle should begin automatically as soon assulfur is detected.16.3 When the analysis is complete, the instrument shouldindicate the sulfur value. Refer to the manufacturers recom-mended procedure.17. Report17.1 Proper identification of the sample.17.2 Sulfur content to t
38、he nearest 0.1 mass %.18. Keywords18.1 organosilanes; silanes; sulfurASTM 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 an
39、y 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 are i
40、nvited either for revision of this standard or for additional standardsand 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 receiv
41、ed 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 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.astm.org).D 6741 01 (2006)3
