1、Designation:D208622Standard Test Method forAcidity in Vinyl Acetate and Acetaldehyde1This standard is issued under the fixed designation D2086;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 pare
2、ntheses 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 totalacidity as acetic acid in refined vinyl acetate and acetaldehyde.1.2 The values stated in SI units are
3、to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 For purposes of determining conformance of an ob-served value or a calculated value using this test method torelevant specifications,test result(s)shall be rounded off“tothe nearest unit”in the last right-hand d
4、igit used in expressingthe specification limit,in accordance with the rounding-offmethod of Practice E29.1.4 For hazard information and guidance,see the suppliersMaterial Safety Data Sheet.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is th
5、eresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.For specific hazard statements,see Section 8.1.6 This international standard was developed in accor-dance with inte
6、rnationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1193 Sp
7、ecification for Reagent WaterE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE200 Practice for Preparation,Standardization,and Storageof Standard and Reagent Solutions for Chemical Analysis3.Summary of Test Method3.1 The specimen is mixed with either
8、 an equal volume ofchilled water or an equal volume of ethyl alcohol and titratedat reduced temperature with aqueous sodium hydroxide solu-tion to a phenolphthalein end point.4.Significance and Use4.1 This test method provides a measurement of total acidityin vinyl acetate and acetaldehyde.The resul
9、ts of these mea-surements can be used for specification acceptance.5.Interferences5.1 Any material or contaminant that will react with NaOHunder the test conditions will affect the results.5.2 Vinyl acetate will decompose on storage,typically byway of hydrolysis,to form acetic acid.5.3 Acetaldehyde
10、will react with oxygen,either dissolved orin a storage container,to form acetic acid.5.4 Various acids or other acidic materials may be present.Common practice,including the method used here,calculatesthese as acetic acid.The actual weight percent of acidicmaterials may be different.6.Apparatus6.1 B
11、uret,10-mL,graduated in 0.05-mL subdivisions.6.2 Erlenmeyer Flask,250-mL capacity.6.3 Graduated Cylinder,50 or 100-mL capacity.6.4 Cold Bath,maintained at 0 C or below.7.Reagents7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall
12、reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.35 on S
13、olvents,Plasticizers,and Chemical Intermediates.Current edition approved Jan.1,2022.Published January 2022.Originallyapproved in 1962.Last previous edition approved in 2012 as D2086 08(2012)which was withdrawn January 2021 and reinstated in January 2022.DOI:10.1520/D2086-22.2For referenced ASTM stan
14、dards,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 19428-2
15、959.United StatesThis 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 issued by the World Trade Organization Technical B
16、arriers to Trade(TBT)Committee.1where such specifications are available.3Other 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.7.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water as definedby Type IV or higher purity of Specification D1193.7.3 Ethyl Alcohol(Ethanol),95 volume%,minimum.NOTE1Denatured ethyl alcohol conforming
