ASTM_D_1726_-_11.pdf

Designation:D172611Standard Test Methods forHydrolyzable Chloride Content of Liquid Epoxy Resins1This standard is issued under the fixed designation D1726;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.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 These test methods cover the determination of the easilyhydrolyzable chloride content of liquid epoxy resins which aredefined as the reaction product of a chlorohydrin and a di-orpolyfunctional phenolic compound.NOTE1There is no known ISO equivalent to this standard.1.1.1 In Test Method A,the easily hydrolyzable chloride issaponified with potassium hydroxide and directly titrated withhydrochloric acid.This test method can be used for concen-trations of 1 weight%and below.1.1.2 In Test Method B,the easily hydrolyzable chloride isagain saponified with potassium hydroxide,then titrated po-tentiometrically with silver nitrate.This test method can beused for concentrations of 5 to 2500 ppm hydrolyzablechloride.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 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 Sections 10 and 16.2.Referenced Documents2.1 ASTM Standards:2D329 Specification for AcetoneD841 Specification for Nitration Grade TolueneD1193 Specification for Reagent WaterD3620 Specification for Glacial Acetic AcidD6440 Terminology Relating to Hydrocarbon ResinsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 The terminology in these test methods follows thestandard terminology defined in Terminology D6440.3.2 Definitions:3.3 hydrolyzable chloride,nthe low level chlorine-containing components of the liquid epoxy resin,typicallyresidual chlorohydrin ethers,which react with water or alcoholto form hydrochloric acid(HCl).4.Summary of Test Method4.1 The sample is refluxed in the presence of a knownamount of 0.1 N alcoholic potassium hydroxide to saponify thehydrolyzable chlorides.4.2 Test Method AThe amount of potassium hydroxideconsumed in the hydrolysis is a measure of the hydrolyzablechloride content of the resin.4.3 Test Method BThe amount of potassium chloridedetected by direct titration with standard silver nitrate solutionis a measure of the hydrolyzable chloride content of the resin.5.Significance and Use5.1 The hydrolyzable chloride content of liquid epoxy resinsis an important variable in determining their reactivity and theproperties of coatings made from them.These test methodsmay be used to determine the hydrolyzable chloride content ofmanufactured epoxy resins and confirm the stated hydrolyzablechloride content of purchased epoxy resins.6.Interferences6.1 Unless stated otherwise,the following interferencesapply to both test methods:6.1.1 Test Method AAlkaline substances easily titratableby HCl,can impact the analysis resulting in lower thanexpected results.Likewise,acidic species,that may behave asthe HCl titrant can impact the analysis resulting in higher thanexpected results.Liquid epoxy resin samples should be neutralwhen analyzed by this test method.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee D01.33 on Polymers and Resins.Current edition approved June 1,2011.Published June 2011.Originallyapproved in 1960.Last previous edition approved in 2003 as D1726 03.DOI:10.1520/D1726-11.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.1.2 Test Method BThiocyanate,cyanide,sulfide,bro-mide,iodide,or other substances capable of reacting withsilver ion,as well as substances capable of reducing silver ionin acidic solutions will impact the analysis resulting in higherthan expected results.6.1.3 Test Methods A and B(using a visual indicator)maynot be applicable to samples containing heat sensitive impuri-ties,leading to high color in the reacted solution.7.Purity of Reagents7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee onAnalyti