ASTM_D_4415_-_05.pdf

Designation:D 4415 05Standard Test Methods forDetermination of Dimer in Acrylic Acid1This standard is issued under the fixed designation D 4415;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(e)indicates an editorial change since the last revision or reapproval.1.Scope*1.1 Test Method ADescribes a chemical(titrametric)pro-cedure for the determination of acrylic acid dimer in acrylicacid.This procedure may be applicable to other unsaturatedorganic acids.1.2 Test Method BDescribes a gas chromatographic pro-cedure for the determination of acrylic acid dimer in acrylicacid.Other impurities may also be determined simultaneously.1.3 The following applies to all specified limits in thisstandard;for purposes of determining conformance with thisstandard,an observed value or a calculated value shall berounded off“to the nearest unit”in the last right-hand digitused in expressing the specification limit,in accordance withthe rounding-off method of Practice E 29.1.4 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.5 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 8.2.Referenced Documents2.1 ASTM Standards:2D 268 Guide for Sampling and Testing Volatile Solventsand Chemical Intermediates for Use in Paint and RelatedCoatings and MaterialsD 1193 Specification for Reagent WaterD 4052 Test Method for Density and Relative Density ofLiquids by Digital Density MeterE 29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE 200 Practice for Preparation,Standardization,and Stor-age of Standard Solutions for Chemical Analysis3.Summary of Test Methods3.1 Test Method AThe acid specimen is neutralized andthe dimer(Acrylic acid dimer,CH2=CH-COO-CH2-CH2-COOH)determined by saponification and titration.Purity ofthe acid can also be determined by carrying out the firstneutralization,quantitatively,but this is not covered in thismethod.3.2 Test Method BAn internal standard,n-dodecane,isadded to the sample and then introduced into a gas chromato-graph containing an appropriate capillary column for separa-tion.The separated components are measured in the columneffluent by a detector and recorded as a chromatogram.Thepeak areas are measured and the concentration of the compo-nents of interest are calculated by reference to the internalstandard.4.Significance and Use4.1 These test methods provide a measurement of the dimercontent of acrylic acid.The results of this measurement can beused for specification purposes but must be on an as-shippedbasis since the dimer content will vary with the age and thestorage temperature of the acrylic acid.5.Interferences5.1 Test Method AIf present,ester impurities present inthe acrylic acid will be determined as dimer.5.2 Test Method BImpurities having the same or similarretention times as the acrylic acid on the column used maycause abnormally high results.6.Apparatus6.1 Test Method A:6.1.1 Pressure Bottle,200 to 350-mL capacity,with lever-type closure and made of heat-resistant glass.6.1.2 Container for Pressure Bottle A suitable safetydevice to contain the pressure bottle.A metal container with ahinged top and perforated bottom,a strong synthetic fabric orcanvas bag,or a safety shield may be used.6.1.3 Open-Top Vial,3 to 5-mLcapacity,of such diameter tofit the pressure bottle.6.1.4 Buret,100-mL capacity.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 Solvents,Plasticizers and Chemical Intermediates.Current edition approved May 15,2005.Published July 2005.Originallyapproved in 1984.Last previous edition approved in 2000 as D 4415 91(2000)e1.2For 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.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.6.1.5 Buret,50-mL capacity,calibrated.6.1.6 Boiling Water Bath.6.2 Test Method B:6.2.1 Gas ChromatographAny gas chromatograph havinga flame ionization detector(FID)or any other detector,provided the system has sufficient sensitivity and stability toobtain,for a 0.01%impurity in the specimen,a recorderdeflection of at least 20 mm at a signal to noise ratio of at least5 to 1.6.2.1.1 The ch