ASTM_D_6741_-_10_2019.pdf

Designation:D674110(Reapproved 2019)Standard Test Methods forSilanes Used in Rubber Formulations(bis-(triethoxysilylpropyl)sulfanes):Sulfur Content1This standard is issued under the fixed designation D6741;the number immediately following the designation indicates the 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 These test methods cover the determination of the sulfurcontent of silanes,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 stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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 safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Significance and Use3.1 The sulfur content can be used to characterize a silane oran admixture of silane and carbon black.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 solution,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 Analytical 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,10 cm3.5.9 Syringe,0.5 cm3.5.10 Titration Beakers.5.11 Magnetic Stirrer,with stirring rod.5.12 Filter Paper,for Schoeniger combustion(35 35 70mm).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 reagents1These test methods are under the jurisdiction of ASTM Committee D11 onRubber and Rubber-like Materials and are the direct responsibility of SubcommitteeD11.20 on Compounding Materials and Procedures.Current edition approved Nov.1,2019.Published December 2019.Originallyapproved in 2001.Last previous edition approved in 2015 as D6741 10(2015).DOI:10.1520/D6741-10R19.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 shall 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 accuracy ofthe determination.6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water conformingto Specification D1193.6.3 2-propanol 99%.6.4 Hydrogen Peroxide Solution,(5%)as absorbing liquid.6.5 Barium Perchlorate Solution,0.005 mol/dm3in2-propanol/water.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 Water.6.9 Oxygen.6.10 Sulfanilic Acid,(certified standard for elemental analy-sis).7.Prepara