ASTM_D_1652_-_11e1.pdf

Designation:D1652111Standard Test Method forEpoxy Content of Epoxy Resins1This standard is issued under the fixed designation D1652;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.1NOTEEditorial corrections were made throughout in May 2012.1.Scope*1.1 This test method covers the procedure for manual andautomatic titration of epoxy resins for the quantitative deter-mination of the percent epoxide content from 0.1 to 26%epoxide.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 Section 6.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent Water2.2 Other Documents:OSHA Regulations,29 CFRparagraphs 1910.1000 and1910.120033.Summary of Test Method3.1 The resin is dissolved in a suitable solvent and theresulting solution is titrated with hydrogen bromide eitherdirectly or in situ.The hydrogen bromide reacts stoichiometri-cally with epoxy groups to form bromohydrins;therefore,thequantity of acid consumed is a measure of the epoxy content.3.1.1 In the Manual Titration Method,the titration is withstandard perchloric acid in the presence of an excess oftetraethylammonium bromide.Hydrogen bromide generated insitu by the addition of perchloric acid to the quaternaryammonium halide rapidly opens the oxirane ring.3.1.2 In the Automatic Titration Method,the reaction ismeasuring the millivolt(MV)potential as perchloric acid isadded,which combines with the bromide to form the hydro-bromic acid,which reacts with the epoxide group.As thereaction progresses,the potential will gradually increase untilthe reaction nears completion at which point the potentialincreases very quickly.The titrator measures the rate of thereaction by calculating the change in potential between per-chloric acid addition increments.When the change in potentialbegins to decrease,the titrator determines that the titration iscomplete.The epoxide content is calculated using the reagentfactor entered by the user during standardization,the weight ofthe sample,and the volume of perchloric acid added duringtitration.4.Significance and Use4.1 The epoxy content of epoxy resins is an importantvariable in determining their reactivity and the properties ofcoatings made from them.These test methods may be used todetermine the epoxy content of manufactured epoxy resins andconfirm the stated epoxy content of purchased epoxy resins.5.Reagents5.1 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 on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused,provided it is first ascertained that the reagent is of1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.33 on Polymers and Resins.Current edition approved Nov.1,2011.Published January 2012.Originallyapproved in 1969.Last previous edition approved in 2004 as D1652 04.DOI:10.1520/D1652-11E01.2For 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.3Available from U.S.Government Printing Office Superintendent of Documents,732 N.Capitol St.,NW,Mail Stop:SDE,Washington,DC 20401,http:/www.access.gpo.gov.4Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 sufficiently high purity to permit its use without lessening theaccuracy of the determination.5.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water as definedby Type II of Specification D1193.6.Hazards6.1 Hydrogen bromide and glacial ace