1、Designation:D590205(Reapproved 2015)Standard Test Method forRubberDetermination of Residual Unsaturation inHydrogenated Nitrile Rubber(HNBR)by Iodine Value1This standard is issued under the fixed designation D5902;the number immediately following the designation indicates the year oforiginal adoptio
2、n 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 Wiijs procedure for thedetermination of unsaturation(i
3、odine value)in hydrogenatednitrile rubbers.1.2 This test method is applicable only to those hydroge-nated nitrile rubbers derived from copolymers of acrylonitrileand butadiene.1.3 Iodine values are reported in centigrams of iodine pergram of HNBR cg(I2)/g.Higher iodine values indicate higherlevels o
4、f unsaturation.1.4 This test method is appropriate for calculating thepercent residual unsaturation of hydrogenated nitrile rubber ifthe iodine value of the base polymer before hydrogenation hasbeen determined.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurem
5、ent are included in thisstandard.1.6 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 limitation
6、s prior to use.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1959 Test Method for Iodine Value of Drying Oils andFatty Acids(Withdrawn 2006)3D4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries3.Summ
7、ary of Test Method3.1 Asample of the raw,unvulcanized rubber is dissolved inchloroform.3.2 The dissolved sample is reacted with Wiijs solution.3.3 When the reaction is completed,potassium iodide solu-tion is added.3.4 The resultant solution is then back-titrated with sodiumthiosulfate solution and t
8、he iodine value is calculated.4.Significance and Use4.1 Hydrogenated nitrile rubbers are available at differentlevels of unsaturation and different acrylonitrile content.Highly saturated grades offer optimum resistance to aging,such as exposure to heat,ozone and chemicals,and can becured effectively
9、 only with peroxides or high energy radiation.4.2 Partially unsaturated grades can be cured by sulfursystems in addition to peroxides and high energy radiation.4.3 This test method provides a technique to determine theunsaturation level of hydrogenated nitrile rubbers in the raw,unvulcanized state.I
10、t can be used for research anddevelopment,quality control,and referee purposes.5.Apparatus5.1 Erlenmeyer Flasks,with ground glass stoppers(300mL).5.2 Flask Shaker.5.3 Pipets.5.4 Constant Temperature Bath.6.Reagents6.1 Reagent grade chemicals shall be used in all tests.Allreagents shall conform to th
11、e specifications of the Committeeon Analytical Reagents of the American Chemical Society.41This 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 June 1,2015.Published September 2
12、015.Originallyapproved in 1996.Last previous edition approved in 2010 as D5902 05(2010).DOI:10.1520/D5902-05R15.2For 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 stand
13、ards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For Suggestions on the testing of reagents notlisted by the American Ch
14、emical Society,see Annual Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United S
15、tates1 Other grades may be used,provided it is first ascertained thatthe reagent is of sufficiently high purity to permit its usewithout lessening the accuracy of the determination.6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water conformingto
16、 Type I of Specification D1193.6.3 Chloroform.6.4 Wiijs Solution(prepared in accordance with Test MethodD1959).6.5 Potassium Iodide Solution(prepared in accordance withTest Method D1959).6.6 0.1 N Sodium Thiosulfate Solution(prepared in accor-dance with Test Method D1959).6.7 Starch Indicator Solution(prepared in accordance withTest Method D1959).7.Procedure7.1 If the approximate level of unsaturation is known,thefollowing sample sizes are recommended:Approximate unsaturation levelSample weight