1、Designation:D 4415 91(Reapproved 2000)e1Standard 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 revis
2、ion.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.e1NOTEFootnote references to commercial manufacturers were deleted editorially in November 2000.1.Scope1.1 Test Method ADescribes a chemical(ti
3、trametric)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 deter
4、mined simultaneously.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 u
5、se.For specific hazardstatements,see Section 8.2.Referenced Documents2.1 ASTM Standards:D 268 Guide for Sampling and Testing Volatile Solventsand Chemical Intermediates for Use in Paint and RelatedCoatings and Materials2D 1193 Specification for Reagent Water3D 4052 Test Method for Density and Relati
6、ve Density ofLiquids by Digital Density Meter4E 200 Practice for Preparation,Standardization,and Stor-age of Standard Solutions for Chemical Analysis53.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 sapon
7、ification 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
8、 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 The
9、se 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 Meth
10、od 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 capaci
11、ty,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
12、to 5-mLcapacity,of such diameter tofit the pressure bottle.6.1.4 Buret,100-mL capacity.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 suf
13、ficient 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 chromatograph should be capable of tempera-ture programming.6.2.1.2 The injection port or system should be one suitable1This
14、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 Sept.15,1991.Published November 1991.Originallypubli
15、shed as D 4415 84.Last previous edition D 4415 89.2Annual Book of ASTM Standards,Vol 06.04.3Annual Book of ASTM Standards,Vol 11.01.4Annual Book of ASTM Standards,Vol 05.02.5Annual Book of ASTM Standards,Vol 15.05.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.fo
16、r the capillary column used.Split injection techniques shouldbe used.6.2.2 ColumnA 30 to 50-m long by 0.32-mm insidediameter fused silica capillary column with a 0.2 to 0.3-m filmof a bonded,esterified polyethylene glycol phase.Any othercolumn,capable of providing the necessary separation andprecision,may be used.6.2.3 Sample Introduction SystemAny system capable ofintroducing a representative specimen into the column.Mi-crolitre syringes and autosampler systems have been usedsuccessfully.6.2.4