ASTM_D_7245_-_09_2014.pdf

Designation:D724509(Reapproved 2014)Standard Test Method forMeasuring Total Water and Volatiles in Liquid CoatingsWhich Produce Cure Water Upon Heating1This standard is issued under the fixed designation D7245;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.1.Scope1.1 This test method is designed to measure total waterwhich includes cure water resulting from the heat inducedcondensation reaction of coatings.Cure water cannot bemeasured directly by Test Method D4017.This task is accom-plished by measuring water content in the vapors evolvedduring heating.This test method will yield total water content.This test method also permits for the simultaneous determina-tion of total volatile content.The results of this test methodmay be used to calculate VOC content.Although this testmethod was designed for phenolic coatings,it can be used withother types of coatings.1.2 Materials used for method development and evaluationhad total water values from 20 to 37%.Use of this test methodon coatings outside these values will need to be validated bythe user.1.3 Sample heating is accomplished with a BrinkmannInstruments Model 832 drying oven,2or other mutually agreedupon alternative,passing all of the evolved vapors into a KarlFischer titration vessel.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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 to determine theapplicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3D1193 Specification for Reagent WaterD3925 Practice for Sampling Liquid Paints and RelatedPigmented CoatingsD3960 Practice for Determining Volatile Organic Compound(VOC)Content of Paints and Related CoatingsD4017 Test Method for Water in Paints and Paint Materialsby Karl Fischer MethodE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions:3.1.1 cure water,nwater produced as a product of con-densation reaction during cure.3.1.2 total water,nwater in the liquid coating plus curewater produced by the condensation reaction.4.Summary of Test Method4.1 A measured quantity of coating is added to a tared glassvial which is sealed and then placed into a preheated ovenchamber for the required test duration.Sample is heated at110C for one hour.The volatiles are passed into a Karl Fischertitration vessel and total water determined.By subtracting thepercent water found in regular Karl Fischer titration,TestMethod D4017,from total water,the percent of cure water canbe determined.With the weights being known and vial sealed,total volatile content is obtained with this method.5.Significance and Use5.1 In the determination of VOC,cure water is treated as aVOC in other test methods,as these methods are unable to1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved July 1,2014.Published July 2014.Originally approvedin 2007.Last previous edition approved in 2009 as D7245 09.DOI:10.1520/D7245-09R14.2Round-robin collaborators used the Model 832 drying oven which were loanedto them by Brinkmann Instruments Westbury,New York 11590.It is not knownwhether this method is applicable to other similar instruments.3For 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 account for cure water.This test method allows taking creditfor cure water as total water is measured,a value whichincludes cure water.5.2 Total water content and volatile content results obtainedwith this method may be used in Practice D3960 to calculateVOC of the coating.6.Apparatus6.1 Glass VialA glass vial measuring 22 mm in diameter,38 mm in height having a capacity of 6 ml capable of beingsealed with a TFE-fluorocarbon septum.6.2 Analytical BalanceCapable of weighing to 60.0001g.6.3 Drying OvenThis instrument is essentially a closedsystem in which the sample is heated within the heatingchamber and the vapors passed to the titration vessel through aconnecting tube.See Fig.1.6.4 Karl Fischer ApparatusSee Test Method D4017.6.5 SyringeMinimum