TM_D_4569
2006
R2017
This 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 isued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.Designation:D4569-06(Reapproved 2017)INTERNATIONALStandard Test Method forRubber Compounding Materials-Determination of Acidity inSulfur1This standard is issued under the fixed designation D4569;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(8)indicates an editorial change since the last revision or reapproval.1.Scope4.Apparatus1.1 This test method covers the determination of the acid4.1 pH Meter;equipped with a glass measuring electrodematerial,which disassociates in distilled water,that is present and calomel reference electrode,operated according to thein sulfur.The acidity is determined by an electrometric or manufacturers directions for optimum performance.visual titration.4.2 10 cm3 Burette,with 0.05 cm3 graduations.1.2 The values stated in SI units are to be regarded as the4.3 Laboratory Glassware,suitable for carrying out thestandard.The values given in parentheses are for informationprocedure as written.only.1.3 This standard does not purport to address all of the5.Reagentssafety concerns,if any,associated with its use.It is the5.1 Purity of Reagents-Reagent grade chemicals shall beresponsibility of the user of this standand to establish appro-used in all tests.Unless otherwise indicated,it is intended thatpriate safety and health practices and determine the applica-all reagents conform to the specifications of the Committee onbility of regulatory limitations prior to use.Analytical Reagents of the American Chemical Society where1.4 This international standard was developed in accor-such specifications are available.3 Other grades may be used,dance with internationally recognized principles on standard-provided it is first ascertained that the reagent is of sufficientlyization established in the Decision on Principles for thehigh purity to permit its use without lessening the accuracy ofDevelopment of International Standards,Guides and Recom-the determination.mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.5.2 Bromothymol Blue-Dissolve 0.1 g of 3,3-dibromothymolsulfonphthalein in 100 cm3 of 20%methanol2.Referenced Documentsor use commercical preparations.2.1 ASTM Standards:25.3 Sodium Hydroxide,0.01 N.D4483 Practice for Evaluating Precision for Test Method6.ProcedureStandards in the Rubber and Carbon Black ManufacturingIndustries6.1 Weigh 10.0 g of sulfur into a 500-cm2 beaker,and wetthe sample with 25 cm3 of alcohol.3.Significance and Use6.2 Add 200 cm3 of distilled water,and stir the wetted sulfur3.1 This test method provides a means of determining thethoroughly.acidity of sulfur and may be used for quality control,researchand development,or for any other reason for which such a6.3 Place the pH meter electrode in the solution and titratedetermination is required.A low acidity value indicates to thewith 0.01 N NaOH to a pH of 7.0.Stir the mixture constantlyuser that the sulfur used should not adversely affect thewhile titrating.When nearing the end of the titration,wait untilvulcanization system.the pH reading has reached equilibrium before adding addi-tional NaOH solution to prevent overshooting the end point.This test method is under the jurisdiction of ASTM Committee D11 on Rubber6.4 If a pH meter is unavailable,add 10 drops of bromo-and Rubber-like Materials and is the direct responsibility of Subcommittee D11.11thymol blue indicator and titrate as above.on Chemical Analysis.Current edition approved May 1,2017.Published May 2017.Originallyapproved in 1986.Last previous edition approved in 2012 as D4569-06(2012).3 Reagent Chemicals,American Chemical Society Specifications,AmericanDOI:10.1520/D4569-06R17.Chemical Society,Washington,DC.For suggestions on the testing of reagents not2 For referenced ASTM standards,visit the ASTM website,www.astm.org,orlisted by the American Chemical Society,see Analar Standards for Laboratorycontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMChemicals,BDH,Poole,Dorset,U.K,and the United States PharmacopeiaStandards volume information,refer to the standards Document Summary page onand National Formulary,U.S.Pharmaceutical Convention,Inc.(USPC),Rockville,the ASTM website.MD.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesCopyright by ASTM Intl(all rights reserved);Sat Sep 30 12:40:10 EDT 20171Downloaded/printed byUniversity of Edinburgh(University of Edinburgh)pursuant to License Agreement.No further reproductions authorized.4D4569-06(2017)6.5 Important:Titrate a blank(no sulfur)using the sameTABLE 1 Type 1 Precision Results-Acidity,%x 100amounts of alcohol and water to a pH 7.0 end point.SubtractWithin Laboratory Between LaboratoryMaterialthe amount used for the blank from the amount used to titrateAverageS,a sulfur sample in order to determine the acidity of the sulfurOil Treated,90%0.210.23150.65510.24190.6847sample.Insoluble Sulfur-AOil Treated,90%0.360.35050.99200.35050.9920Insoluble Sulfur-B7.CalculationGeneral Purpose3.730.32660.92430.01372.30277.1 Calculate the percent acidity,A,(as H2SO)in accor-Ground Sulfur1.430.30620.86650.57931.6394dance with the following equation:Pooled ValuesA S=repeatability standard deviation.A=4.9XVX N/W(1)r=repeatability=2.83 x the square root of the repeatability variance.Se=reproducibility standard deviation.where:R=reproducibility 2.83 x the square root of the reproducibility variance.No values omitted.volume of NaOH for sample-volume NaOH for blank.cm,normality of NaOH solution,andby this multiplication factor,that is,S(percent ash x 100)/100 S(actual公sample mass,g.or true percent basis).9.6 The precision of this test method may be expressed in8.Reportthe format of the following statements which use an appro-8.1 Report the following information:priate valueof rR.(r).or(R),that is,that value to be used in8.1.1 Percent acidity as H2SO.decisions about test results(obtained with the test method).8.1.2 If the pH of the sulfur solution is greater than 7.0 andThe appropriate value is that value of r or R associated with ano titrant is needed,report the result as basic.mean level in Table I closest to the mean level underconsideration at any given time,for any given material in9.Precision and Biasroutine testing operations.9.1 This precision and bias section has been prepared in9.7 Repeatability-The repeatability,r.of this test methodaccordance with Practice D4483.Refer to Practice D4483 forhas been established as the appropriate value tabulated interminology and other statistical details.Table 1.Two single test results,obtained under normal test9.2 The precision results in this precision and bias sectionmethod procedures,that differ by more than this tabulated rgive an estimate of the precision of this test method with the(for any given level)must be considered as derived frommaterials(rubbers)used in the particular interlaboratory pro-different or nonidentical sample populations.grams as described below.The precision parameters should not9.8 Reproducibility-The reproducibility,R,of this testbe used for acceptance/rejection testing of any group ofmethod has been established as the appropriate value tabulatedmaterials without documentation that they are applicable toin Table 1.Two single test results obtained in two differentthose particular materials and the specific testing protocols thatlaboratories,under normal test method procedures,that differinclude this test method.by more than the tabulated R(for any given level)must be9.3 A Type I(interlaboratory)precision was evaluated inconsidered to have come from different or nonidentical sample1986.Both repeatability and reproducibility are short term.Apopulationsperiod of a few days separates replicate test results.A test resultNoTE 2-The values of r and R are relatively large,whereas the averageis the mean value,as specified by this test method,obtained onor mean test level is small(close to zero).This is typical for this type oftwo determinations or measurements of the property or param-precision measurement process.This should be kept in mind whenever useeter in question.is made of r and R.9.4 Three different materials were used in the interlabora-9.9 The relative repeatability(r)and reproducibility(R)tory program.These were tested in seven laboratories on twohave been omitted from Table I since the level of values testeddifferent days.was extremely low and approached the limits of sensitivity ofthe test method.Under these circumstances,the relative values9.5 The results of the precision calculations for repeatabilitybecome trivial.and reproducibility are given in Table 1,in ascending order ofmaterial average or level,for each of the materials evaluated.9.10 Bias-In test method terminology,bias is the differencebetween an average test value and the reference(or true)testNorE 1-The percent acidity values have been multiplied by 100 toproperty value.Reference values have not been evaluated foravoid leading zeros in Table 1.The values of S.r.S.and R are influencedthis test method.Bias,therefore,cannot be determined.10.KeywordsSupporting data have been filed at ASTM Intemational Headquarters and maybe obtained by requesting Research Report RR:D11-1046.10.1 acidity;oil-treated sulfur;sulfurCopyright by ASTM Intl(all rights reserved):Sat Sep30 12:40:10 EDT 2017 2Downloaded/printed byUniversity of Edinburgh(University of Edinburgh)pursuant to License Agreement.No further reproductions authorized4D4569-06(2017)ASTM Intemational takes no position 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