1、BRITISH STANDARD BS EN 13955:2002 Surface active agents Determination of Krafft point and solubility of ionic surface active agents The European Standard EN 13955:2002 has the status of a British Standard ICS 71.100.40 BS EN 13955:2002 This British Standard, having been prepared under the direction
2、of the Materials and Chemicals Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 20 December 2002 BSI 20 December 2002 ISBN 0 580 41014 5 National foreword This British Standard is the official English language version of EN 139
3、55:2002. The UK participation in its preparation was entrusted to Technical Committee CII/34, Methods of test for surface active agents, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British St
4、andards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. T
5、his publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible in
6、ternational/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the E
7、N title page, pages 2 to 9 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN13955 December2002 ICS71.100.40 Englishversion Surfac
8、eactiveagentsDeterminationofKrafftpointand solubilityofionicsurfaceactiveagents AgentsdesurfaceDterminationdupointdeKrafftetde lasolubilitdesagentsdesurfaceioniques GrenzflchenaktiveStoffeBestimmungvonKrafftPunkt undLslichkeitvonionischengrenzflchenaktivenStoffen ThisEuropeanStandardwasapprovedbyCEN
9、on23October2002. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManageme
10、ntCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandar
11、dsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:rue
12、deStassart,36B1050Brussels 2002CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN13955:2002EEN13955:2002(E) 2 Contents page Foreword3 1 Scope 4 2 Normativereferences 4 3 Termsanddefinitions. .4 4 Principle5 5 Apparatus .5 6 Procedure .6 7 Expressionof
13、results . .7 8 Precision.8 9 Testreport . .8 AnnexA (informative) GraphicalrepresentationoftheKrafftpoint 9EN13955:2002(E) 3 Foreword Thisdocument(EN13955:2002)hasbeenpreparedbyTechnicalCommitteeCEN/TC 276,“Surfaceactive agents“,thesecretariatofwhichisheldbyAFNOR. ThisEuropeanStandardshallbegiventhe
14、statusofanationalstandard,eitherbypublicationofanidenticaltextor byendorsement,atthelatestbyJune2003,andconflictingnationalstandardsshallbewithdrawnatthelatestby June2003. AnnexAisinformative. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowing countriesarebo
15、undtoimplementthisEuropeanStandard:Austria,Belgium,CzechRepublic,Denmark,Finland, France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Spain, Sweden,SwitzerlandandtheUnitedKingdom.EN13955:2002(E) 4 1Scope ThisEuropeanStandardspecifiesamethodforthedeterminationofth
16、esolubilityofionicsurfaceactiveagentsin waterasafunctionofconcentrationandtemperatureandforthedeterminationoftheKrafftpointbygraphical evaluationofthemeasurementresults. Inthetemperaturerangefrom0 Cto90 C,thesolubilityisdeterminedwithoutanylimitationsiftheviscosityof thesolutiondoesnotexceedabout700
17、mPas. Attemperaturesbelow0 C,determinationisonlypossibleifthesolventdoesnotfreeze. Themethodisapplicablebothtopuresurfaceactiveagentsandtotechnicalproductsopticallyclearandnot undulycolouredsolutions. Thesolubilitybothofsolidandliquidsurfaceactiveagentsandofaqueoussolutionsofsurfaceactiveagentsis de
18、terminedbythemethodspecified. 2 Normativereferences ThisEuropeanStandardincorporatesbydatedorundatedreference,provisionsfromotherpublications.These normativereferencesarecitedattheappropriateplacesinthetextandthepublicationsarelistedhereafter.For datedreferences,subsequentamendmentstoorrevisionsofan
19、yofthesepublicationsapplytothisEuropean Standardonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthelatesteditionofthe publicationreferredtoapplies(includingamendments). ENISO3696, WaterforanalyticallaboratoryuseSpecificationandtestmethods(ISO3696:1987). ISO383, LaboratoryglasswareI
20、nterchangeableconicalgroundjoints . 3 Termsanddefinitions ForthepurposesofthisEuropeanStandard,thefollowingtermsanddefinitionsapply: 3.1 solubility concentrationatthattemperatureatwhichthecloudinessdisappearsagainonheatingacloudysurfaceactive agentsolution NOTE Solutionsofionicsurfaceactiveagentsbec
21、omecloudywhencooledassoonasthesaturationconcentration associatedwithaparticulartemperatureisexceeded.Foragivensurfaceactiveagentconcentration,thetemperatureatwhich cloudinessappearsdecreasesasthesolubilityofthesurfaceactiveagentincreases.Thiscloudinessdisappearsagainifthe solutionisheated. 3.2 Kraff
22、tpoint i)temperatureatwhichthesolubilityofanionicsurfaceactiveagentinwaterchangessuddenlyor ii)temperatureatwhichthesaturationconcentrationofthesurfaceactiveagentreachesitscriticalmicelle concentration(SeeannexA)EN13955:2002(E) 5 4Principle Anaqueoussolutionofthechosenconcentrationofthesampleiscoole
23、dwhilestirringcontinuouslyuntilitis completelycloudy.Thesolutionisthenheatedslowlyatarateof0,5 C/minuntilitisclearagainandthe temperatureatwhichthisoccursisrecorded.TodeterminetheKrafftpoint,themeasurementsobtainedatvarious concentrationsareplottedingraphform.Thisyieldsasolubilitycurvehavingthetwobr
24、anchesaandb,theKrafft point T k beingindicatedbythepointatwhichtheyintercept. 5Apparatus 5.1 TestapparatusaccordingtoFigure1,consistingof: a) thetestvesselwithgroundsocket45/40inaccordancewithISO383; b) theheatingjacketwhichshallbeconnectedtoacirculatingthermostat; c) thestopperwithgroundjoint45/40i
25、naccordancewithISO383,forpreventingthatairisbeingstirredintothe surfaceactiveagentsolution; d) thestraightthermometerwithascaledivisionof0,1 C,alengthofatleast100mmandameasurementrange matchedtothetemperaturetobemeasured. NOTE1 Thethermometercanbeattachedwithadhesivetapetotheguideforthestirrerspindl
26、e(5.1e)ortoastandby meansofaclamp. NOTE2 Thethermometerandthebasketstirrer(5.1f)donotcompletelysealthetestapparatussoastoenableanyair bubblesintroducedintothetestsolutiontoescape.Thestopper(5.1c),however,adequatelyseparatestheliquidaboveitfr om theliquidinthemeasurementchambersothattheliquidabovethe
27、stopperremainsstationaryevenduringvigorousstirringand noaircanpenetrateintothemeasuringchamber; e) thestirrerspindleofstainlesssteel; f) thebasketstirrerofstainlesssteel. 5.2 Analyticalbalance .,accurateto0,1mg. 5.3 Onemarkpipettes withnominalcapacitiesof20mland100ml. 5.4 Conicalflask ,wideneck,with
28、anominalcapacityof250ml.EN13955:2002(E) 6 Dimensionsinmillimetres Key 1 Testvessel 2 Heatingjacket 3 Stopper 4 Thermometer 5 Stirrershaft 6 Basketstirrer 7 Tothermostat 8 Fromthermostat Figure1Testapparatus 6Procedure Solutionswhicharecloudyduetodispersedcontaminantsshallbefiltered,butstepsshallbeta
29、kentoensurethat thetemperatureisabovethesolubilitylimitandnochangeoccursinthesurfaceactiveagentconcentrations. Weighthesample,tothenearest0,01g,intotheconicalflask(5.4),usetheonemarkpipettes(5.3)toadd120ml ofwatergrade3, W A ,inaccordancewithENISO3696andstirintheclosedflask,heatingifnecessary,untilt
30、he sampleiscompletelydissolved.Thentransferthesolutiontothetestvessel(5.1a)andfitthestopper(5.1c), thermometer(5.1d)andbasketstirrer(5.1f)andstirrerspindle(5.1e).EnsurethatthetemperatureofthetestEN13955:2002(E) 7 vesselisaboutthesameasthatofthetestsolution.Thequantityofsolutionshallbesuchthatthestop
31、peris coveredbyalayerofsolutionabove1cmdeep.Removeanyairbubblesinthesolutionintroducedwhenthe surfaceactiveagentisdissolvedorwhiletransferringitbyslowlystirringandheatingthesolution.Thenlowerthe temperatureusingthethermostatuntilthesolutioniscompletelycloudy.Whenthispointisreached,heatthe solutionat
32、arateof0,5 C/minwhilestirringuntilitiscompletelyclearagain. Whenheatingthecloudysurfaceactiveagentsolution,alwaysensurethatequilibriumisestablished,particularlyif therateatwhichthesurfaceactiveagentdissolvesislow. NOTE1 Tocheckthatthesolutionissaturatedattheclearpoint,itcanbekeptforafewminuteswhiles
33、tillcloudyata temperaturejustbelowtheclearpointmeasured.Ifthesolutionbecomesclearatthistemperature,equilibriumhadnotyetbee n established. Iftheequilibriumhasnotbeenestablished,repeatthedeterminationoftheclearpointatalowerheatingrate. Notethetemperatureatwhichthetestsolutionisclearagain. Toplotthesol
34、ubilitycurve,determinethemeasuredpointsforatleastsixdifferentsurfaceactiveagent concentrations,ensuringthatthecurvebranchesaandbinthephasediagramshowninFigureA.1eachcontain threemeasurements.Ifbothcurvesaandbarenotstraightlines,whichisgenerallythecase,determinethe numberofmeasurementsnecessaryforthe
35、solubilitycurvebycarryingoutpreliminaryexperiments.Carryouttwo determinationswhichareindependentofeachotherforeverymeasuredvalue. NOTE2 Aplotofthesolubilitycurvecanbeobtainedmuchmorequicklyifthedeterminationsarecarriedoutsimultaneously inseveraltestvesselswhichcontaindifferentsurfaceactiveagentconce
36、ntrations.Itisadvisabletochoosetheconcentratio ns sothatthemeasuredvaluesareabout5 Cto10 Capart. 7 Expressionofresults RecordtheconcentrationschosenandthemeasuredvaluesobtainedasshowninTable1. Table1 Serial numberof test Sample Massof solvent Sampleconcentration Measured temperature Typeand identifi
37、cation Initialsample mass Massof substance in100gof solvent Massof substance in100gof solution g g g/100g g/100g C ThevalueoftheKrafftpointindegreesCelsiusisgivenbytheinterceptofthetwobranchesaandbofthephase diagramshowninFigureA.1obtainedbyplottingthemeasuredvalueswiththetemperature, T,indegreesCel
38、sius ashorizontalaxisandtheconcentrationing/100gofsolventorasmassfractioninpercentasverticalaxis.EN13955:2002(E) 8 8Precision Theresultsofduplicateandmultipledeterminationsshallnotdifferfromoneanotherbymorethan0,5 C.Ifthisis notthecase,thedeterminationsshallberepeated. 9 Testreport Thetestreportshal
39、lincludethefollowinginformation: a) areferencetothisEuropeanStandard; b) thevaluesandinformationcontainedinTable1; c) theKrafftpoint,indegreesCelsius; d) anydeviationsfromthisEuropeanStandard; e) thedateoftesting.EN13955:2002(E) 9 Annex A (informative) GraphicalrepresentationoftheKrafftpoint Express
40、edintheformofagraph(FigureA.1),theKrafftpointisthetemperature T k atthetriplepointinthephase diagramofthesurfaceactiveagent/watersysteminwhichtheconcentrationandtemperaturearethevariables.In thesimplestcase,thisphasediagramisdividedintothreeregionsasfollows. regionI: thisisaregionoflowconcentrationi
41、nwhichallthesurfaceactiveagentisdissolvedinmonomolecularform; regionII: thisisaregionofhighconcentrationwhichisabovetheKrafftpointandinwhichthesolutioncontainsnotonly truedissolvedmoleculesbutalsomicelles; region III: thisisaregionoffairlyhighconcentrationwhichisbelowtheKrafftpointandinwhichthesurfa
42、ceactiveagent assumeseithertheformofcrystalsorofagel. Theabsolutevaluesatwhichtheconcentrationisdescribedas“low“,“high“and“fairlyhigh“alwaysdependina givensystemonthenatureofthesurfaceactiveagentandnofigurescanthereforebespecifiedhere; ThebranchesaandbofthecurveinFigureA.1arethesolubilitycurveofthes
43、urfaceactiveagentaboveand belowtheKrafftpoint,whereasthebranchcshowsthemicelleformationconcentrationasafunctionof temperature. Key 1 Concentration 2 Temperature FigureA.1Typicalphasediagramofasurfaceactiveagent/watersystem TheKrafftpointofhomologoussurfaceactiveagentsincreaseswiththelengthofthehydrocarbonchain.BS EN 13955:2002 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible fo
