ASTM_D_3314_-_02_2012.pdf

Designation:D331402(Reapproved 2012)Standard Test Method forRubberChemical Analysis for Polystyrene Blocks In SBR(Styrene-Butadiene Rubber)and Styrene-ReinforcedLatices1This standard is issued under the fixed designation D3314;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 longpolystyrene blocks in SBR rubbers and styrene-reinforcedlatices.1.2 Percent block styrene content may be determined in therange from 1 to 100%.1.3 This test method is intended for use on gel-freepolymers,but it may be used on polymers containing gel,if ithas been proven that gel does not interfere.1.4 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.For specific hazardstatements,see Section 7.2.Referenced Documents2.1 ASTM Standards:2D1076 Specification for RubberConcentrated,AmmoniaPreserved,Creamed,and Centrifuged Natural LatexD1416 Test Methods for Rubber from Synthetic SourcesChemical Analysis(Withdrawn 1996)3D4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesE145 Specification for Gravity-Convection and Forced-Ventilation Ovens3.Summary of Test Method3.1 The test method is based upon oxidative cleavage of theethylenic bonds in the block copolymer by treating a 1,2-dichlorobenzene solution of the polymer with tertiary butylhydroperoxide(2-methyl-2-hydroperoxypropane)with os-mium tetroxide catalyst.The saturated portions of the polymer,which contain no ethylenic bonds,remain unattacked.Thesmall fragments(low molecular weight aldehydes)and thelow-molecular weight polystyrene fragments from scissionswithin the random copolymer block are soluble in methylalcohol,whereas the detached high-molecular weight polysty-rene from the styrene homopolymer block is insoluble inalcohol.It is therefore possible to separate the high-molecularweight polystyrene,which constitutes the homopolymer block,from the polymer solution.4.Significance and Use4.1 This test method is suitable for manufacturing control,development,and research studies.5.Apparatus5.1 Erlenmeyer Flask,or round-bottom flask for use withthe heating mantle,of 250-cm3capacity with ground-glassjoint.An iodine flask is also satisfactory.5.2 Air Condenser,for 5.1.5.3 Beaker,600-cm3.5.4 Graduated Cylinder,50-cm3.5.5 Pipet,1-cm3.5.6 Buret,100-cm3,for dispensing tertiary butyl hydroper-oxide.5.7 Thermometer,to 150C range.5.8 Crucible,Gooch-type,fritted-glass,medium-porosity,25 to 50-cm3size.5.9 Hot Plate,capable of operating to provide 120 to 130Cto boiling solution,or heating mantle for round-bottom flasksoperating in the same temperature range.5.10 Drying Oven,capable of controlling at 100C Type 1Boven in accordance with Specification E145.6.Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended that1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.11 on Chemical Analysis.Current edition approved May 1,2012.Published May 2012.Originallyapproved in 1974.Last previous edition approved in 2006 as D3314 02(2006).DOI:10.1520/D3314-02R12.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 all reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 1,2-Dichlorobenzene.6.3 Methanol.6.4 Osmium Tetroxide(0.004 M Solution in Toluene 1 kg/m3(0.1 g/100 cm3)Protect the solution from light.Decomposi-tion is indicated by formation of a black precipitate.The vaporsare highly toxic.Therefore,use due precaution in reagentpreparation,use,and disposal.One cubic centimetre of thisstock solution is needed for each analysis.In view of thetoxicity of the reagent,the amount of solution prepared shouldnot greatly exceed the number of determinations to be madeover a reasonable period of time,depending on the stability ofthe solution and the wo