ASTM_D_6844_-_10_2019.pdf

Designation:D684410(Reapproved 2019)Standard Test Method forSilanes Used in Rubber Formulations(bis-(triethoxysilylpropyl)sulfanes):Characterization by HighPerformance Liquid Chromatography(HPLC)1This standard is issued under the fixed designation D6844;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 This test method covers the characterization of silanes,or of admixtures of silane and carbon black(see 10.4),of thetype bis-(triethoxysilylpropyl)sulfane by high performanceliquid chromatography.1.2 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:2D5297 Test Methods for Rubber Chemical AcceleratorPurity by High Performance Liquid ChromatographyE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE682 Practice for Liquid Chromatography Terms and Rela-tionshipsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions:3.1.1 SxBis-(triethoxysilylpropyl)polysulfaneorpolysulfide,(EtO)3SiC3H6SxC3H6Si(OEt)33.1.2 S2Bis-(triethoxysilylpropyl)disulfane or disulfide,(EtO)3SiC3H6S2C3H6Si(OEt)33.1.3 S3Bis-(triethoxysilylpropyl)trisulfane or trisulfide,(EtO)3SiC3H6S3C3H6Si(OEt)33.1.4 S3Bis-(triethoxysilylpropyl)tetrasulfaneortetrasulfide,(EtO)3SiC3H6S4C3H6Si(OEt)33.1.5 S3Bis-(triethoxysilylpropyl)pentasulfaneorpentasulfide,(EtO)3SiC3H6S5C3H6Si(OEt)33.1.6 S3Bis-(triethoxysilylpropyl)hexasulfaneorhexasulfide,(EtO)3SiC3H6S6C3H6Si(OEt)33.1.7 S3Bis-(triethoxysilylpropyl)heptasulfaneorheptasulfide,(EtO)3SiC3H6S7C3H6Si(OEt)33.1.8 S3Bis-(triethoxysilylpropyl)octasulfaneoroctasulfide,(EtO)3SiC3H6S8C3H6Si(OEt)33.1.9 S3Bis-(triethoxysilylpropyl)nonasulfaneornonasulfide,(EtO)3SiC3H6S9C3H6Si(OEt)33.1.10 S3Bis-(triethoxysilylpropyl)decasulfaneordecasulfide,(EtO)3SiC3H6S10C3H6Si(OEt)33.1.11 average sulfur chain lengththe weighted averageof the sulfur bridge in the polysulfide mixture.Includes S2toS10species.4.Summary of Test Method4.1 A sample of the silane is analyzed by high performanceliquid chromatography to determine amounts of eachcomponent,the average chain length and the amount ofdissolved elemental sulfur.4.2 Two methods are described:Method A with a constantcomposition of the mobile phase(isocratic),and Method Busing a gradient.Both methods will give similar chromato-grams.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand Rubber-like Materials and is the direct responsibility of Subcommittee D11.20on Compounding Materials and Procedures.Current edition approved Nov.1,2019.Published December 2019.Originallyapproved in 2002.Last previous edition approved in 2015 as D6844 10(2015).DOI:10.1520/D6844-10R19.2For 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.5.Significance and Use5.1 The average sulfur chain length is an important param-eter in determining the behavior of the silane in a rubbermixture.6.Apparatus6.1 HPLC with UV Detector,operating at 254 nm,InletValve with 5 mm3(L)loop,integrator or data system.6.2 Column C18,5 m,4.6 250 mm.6.3 Column Oven.6.4 Analytical Balance,accuracy 60.1 mg.6.5 Hamilton Syringe,100 mm3(L).6.6 Volumetric Pipet,5 cm3.6.7 Volumetric Flasks,50 and 2000 cm3.6.8 Syringe,3 cm3or 5 cm3.6.9 Glass Bottles,5 cm3.6.10 Disposable PTFE Filters,0.20 m,d=25 mm.6.11 Mechanical Flask Shaker.7.Reagents,AR Grade or Equivalent7.1 Reagents for Method A(without gradient):7.1.1 Ethanol,absolute.7.1.2 Methanol.7.1.3 Tetrabutylammoniumbromide.7.1.4 Cyc