ASTM_D_6740_-_15.pdf

Designation:D674015Standard Test Method forSilanes Used in Rubber Formulations(bis-(triethoxysilylpropyl)sulfanes):Residue on Ignition1This standard is issued under the fixed designation D6740;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 determination of the residueonignitionofsilanesofthetypebis-(triethoxysilylpropyl)sulfane,or of admixtures of these silanesand solid carriers,such as carbon black,waxes,or organicpolymers.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 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:2E177 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.Summary of Test Method3.1 In this test method,a sample of the silane is treated withhydrochloric acid and then ignited in a muffle furnace at1000C.The mass retained after this procedure is called theresidue on ignition.It is expressed in percentage of the initialmass.4.Significance and Use4.1 The residue on ignition,which consists essentially ofSiO2,is related to the silicon content of the silane and may beused to verify the composition of the silane.5.Apparatus5.1 Analytical Balance,accuracy 60.1 mg.5.2 Hot Plate or Ventilated Oven,placed in a fume hood.5.3 Muffle Oven,(1000C).5.4 Porcelain Crucible(High-Form),capacity 25 cm3.5.5 Beaker,500 cm3.5.6 Graduated Pipet,20 cm3.5.7 Graduated Cylinder,250 cm3.5.8 Glass Rod.5.9 Desiccator.6.Reagents6.1 Hydrochloric Acid,37%,analytical grade.6.2 Sulfuric Acid,96%,analytical grade.6.3 Deionized Water.6.4 Silica Glass Wool.7.ProcedureNOTE1Preheat porcelain crucibles and silica glass wool used for thetest for 2 h at 1000C in a muffle furnace.Cool to room temperature andstore in a desiccator until needed for the test.7.1 Liquid Silanes:7.1.1 Weigh(tare)a predried crucible and glass wool plug.Remove the glass wool and tare the crucible alone.7.1.2 Weigh approximately 1 g of the liquid silane into thepre-treated crucible to the nearest 0.1 mg.7.1.3 Add 2 cm3of concentrated(96%nominal)sulfuricacid and homogenize by careful agitation.7.1.4 Cover the mixture with pre-treated silica glass wool.7.1.5 Place the crucible into a ventilated oven,placed in afume hood,and raise the temperature to 125C.NOTE2The oven may be replaced by an electrical heating plate if theformer is not available.7.1.6 When most of the acid has been evaporated(usuallyafter 1 h),transfer the crucible into a muffle furnace,previouslybrought to 1000C.7.1.7 Heat for 2 h at 1000C.7.1.8 If the ash is gray or black,continue heating for anadditional 2 h in the muffle furnace at 1000C.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.20 on Compounding Materialsand Procedures.Current edition approved June 1,2015.Published July 2015.Originally approvedin 2001.Last previous edition approved in 2010 as D6740 10.DOI:10.1520/D6740-15.2For 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 States1 7.1.9 Allow to cool in a desiccator and weigh to the nearest0.1 mg.7.2 Admixtures of Silanes and Carbon Black:7.2.1 Weigh(tare)a pre-dried crucible and glass wool plug.Remove the glass wool and tare the crucible alone.7.2.2 Weigh approximately 1 g of the silane/carbon blackadmixture into the pre-treated crucible to the nearest 0.1 mg.7.2.3 Add 2 cm3of 37%hydrochloric acid and homogenizeby careful agitation.7.2.4 Cover the contents with the respective glass woolplug.7.2.5 Place the crucible into a ventilated oven,placed in afume hood,and raise the temperature to 125C.NOTE3The oven may be replaced by an electrical heating plate if theformer is not available.7.2.6 When the major part of the acid has been evaporated(usually after 1 h),transfer the crucible into a muffle furnace,previously brought to 1000C.7.2.7 Heat for 2 h at 1000C.7.2.8 If the ash is gray or black,continue to heat the cruciblefor an additional 2 h in the muffle furnace at 1000C.7.2.9 Allow to cool in a desiccator and weigh to the nearest0.1 mg.8.Calculation8.1 Calculate the residue on ignition to the neare