1、Designation:D 1962 85(Reapproved 1995)Standard Test Method forSaponification Value of Drying Oils,Fatty Acids,andPolymerized Fatty Acids1This standard is issued under the fixed designation D 1962;the number immediately following the designation indicates the year oforiginal adoption or,in the case o
2、f revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 This test method c
3、overs the determination of the saponi-fication value of drying oils,bodied oils,fatty acids,andpolymerized fatty acids.1.2 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
4、 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:D 305 Test Method for Solvent-Extractable Material inBlack Pigments2D 1193 Specification for Reagent Water33.Termi
5、nology3.1 Definitions:3.1.1 saponification valuea measure of the alkali reactivegroups in oils and fatty acids and is expressed as the number ofmilligrams of potassium hydroxide that react with 1 g ofsample.4.Significance and Use4.1 The saponification value of oils and fatty acids is ameasure of the
6、 content of ester linkages.For an oil,provided itis not significantly oxidized,the number of ester linkages permolecule(for example,three in a triglyceride),can be used tocalculate the molecular weight of the oil.4.2 A saponification value higher than normal indicates thatthe oil has been oxidized(b
7、lown)or chemically modified,forexample,with other acids such as maleic,fumaric,or phthalic.4.3 Saponification value alone is not a measure of thequality of the oil.4.4 Chemically modified oils may require saponificationtimes longer than 1 h for complete reaction.5.Apparatus5.1 Erlenmeyer Flasks,wide
8、-mouth,alkali-resistant,250 or300-mL capacity.5.2 Condenser Loop.NOTE1Suitable condenser loops are shown in Figs.1 and 2 of TestMethod D 305.5.3 Steam Bath.6.Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents sha
9、ll conform to the Specifications of the Com-mittee on Analytical Reagents of the American ChemicalSociety,where such specifications are available.4Other gradesmay be used,provided it is first ascertained that the reagent isof sufficiently high purity to permit its use without lesseningthe accuracy o
10、f the determination.6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water conformingto Type I of Specification D 1193.6.3 Phenolphthalein Indicator SolutionDissolve 1 g ofphenolphthalein in 100 mL of ethanol(95%),methanol orisopropanol.NOTE2A“mask
11、ed phenolphthalein indicator”may be used withoff-color materials.Prepare by dissolving 1.6 g of phenolphthalein and 2.7g of methylene blue in 500 mL of alcohol.Adjust the pH with sodiumhydroxide(NaOH)or KOH solution so that the greenish blue color isfaintly tinged with purple.The color change is fro
12、m green to purple whengoing from acid to alkali.6.4 Potassium Hydroxide,Alcoholic SolutionPlace 5 to10 g of potassium hydroxide(KOH)(Cautionsee 7.1)in a2-L flask and add 1 to 1.5 L of ethyl alcohol(95%)ordenatured alcohol conforming to Formula No.30 or 3A of theU.S.Bureau of Alcohol,Tobacco and Fire
13、arms.Boil on a1This test method is under the jurisdiction of ASTM Committee D-1 on Paintand Related Coatings,Materials,andApplications,and is the direct responsibility ofSubcommittee D01.32 on Drying Oils.Current edition approved May 31,1985.Published July 1985.Originallypublished as D 1962 61.Last
14、previous edition D 1962 67(1984).2Annual Book of ASTM Standards,Vol 06.03.3Annual Book of ASTM Standards,Vol 11.01.4Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,
15、see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmaceutical Convention,Inc.(USPC),Rockville,MD.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Bo
16、ok of ASTM Standards.Copyright ASTMwater bath under a reflux condenser for 30 to 60 min.Distilland collect the alcohol.Dissolve 40 g of KOH in 1 L of thedistilled alcohol,keeping the temperature below 15C whilethe alkali is being dissolved.This solution should remain clear.6.5 Sulfuric or Hydrochloric Acid,Standard(0.5 N)Addabout 15 mL of concentrated sulfuric acid(H2SO4,sp gr 1.84)(Precautionsee 7.2)or 45 mL of concentrated hydrochloricacid(HCl,sp gr 1.19)(Precautionsee 7.3)to about 900 mLof wa
