1、Designation: D7245 09 (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 adoptio
2、n 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 wate
3、r 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
4、 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 w
5、ater 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 KarlFisch
6、er 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 standa
7、rd 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
8、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 t
9、he 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 coa
10、ting 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 regu
11、lar 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
12、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 J
13、uly 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
14、 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
15、ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1account 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 obtain
16、edwith 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
17、 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 of 1 ml but no more than 5 mlcapacit
18、y equipped without a needle, but with a cap, capable ofproperly dispensing the coating.7. Reagents47.1 Purity of ReagentReagent grade chemicals shall beused in all tests unless otherwise indicated; it is intended thatall reagents conform to the specifications of the committee onAnalytical Reagents o
19、f the American Chemical Society wheresuch specifications are available. Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit use.7.2 Purity of WaterUnless otherwise indicated referencesto water shall be understood to mean reagent grade co
20、nformingto type II of Specification D1193.7.3 Karl Fischer ReagentFor ketones.7.4 Methyl Propyl Ketone (MPK), or other appropriatesolventTechnical Grade.8. Preparation of Apparatus8.1 Connect transfer line from the oven into the Karl Fischerunit so the end of the tubing is beneath the level of the l
21、iquidin the Karl Fischer titration vessel.NOTE 1Equipment tested came equipped with a tapered plug designedfor the tubing to fit through and which was tapered to fit into the KarlFischer unit.NOTE 2Transfer line should be insulated to avoid condensation ofvapors in the line. The use of a heated tran
22、sfer line is preferred.8.2 The air-inlet port shall be attached to a source ofdesiccant-dried air or nitrogen.NOTE 3Testing found no appreciable difference between the two.8.3 Check equipment for leaks.8.4 Precondition the glass vials and septum by heating in anoven at 110C for 30 minutes and storin
23、g in a desiccator untilneeded.9. Calibration and Standardization9.1 Use the procedure specified in Test Method D4017 forcalibration and standardization of the Karl Fischer apparatus.9.2 Run a blank on the Methyl Propyl Ketone (MPK) todetermine if it contains water. If there is water present in theso
24、lvent, proceed to 9.2.1.9.2.1 Weigh a sample of MPK, record as Wsolvent,tothenearest 0.1 mg.9.2.2 Perform Test Method D4017, record the weight per-cent water results as Wwater.10. Procedure10.1 Take a representative sample of the liquid coating inaccordance with Practice D3925.10.2 Thoroughly mix th
25、e sample to be analyzed.NOTE 4Mixing time of 5 minutes has proven adequate for mostsamples.10.3 Should amount of cure water need to be known,determine percent water content on the coating in accordancewith Test Method D4017 (Wws).10.4 Determine Total Water (Wwt) and Volatile content(Wv).10.4.1 Prehe
26、at the Drying oven to 110 6 2C.10.4.2 Set the Airflow to 80 ml/min.10.4.3 Purge transfer line for a period of 5 minutes at anairflow rate of 80 ml/min.NOTE 5Testing found use of empty sealed vial served this purpose.10.4.4 Pretitrate contents of the Karl Fischer titration vesselto endpoint.10.4.5 We
27、igh preconditioned empty vial and septum to thenearest 0.0001 g and record weight (Wt).10.4.6 Using a syringe, draw a sample of coating and capsyringe.10.4.7 Weigh to the nearest 0.0001 g and record (W1).4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washingt
28、on, 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.FIG. 1 Drying
29、 OvenD7245 09 (2014)210.4.8 Transfer approximately 0.2 ml (0.3 g) of the sampleto the glass vial.10.4.9 Cap syringe and re-weigh, record the weight (W2).10.4.10 Add approximately 0.8 ml of Methyl Propyl Ketone(MPK) or other mutually agreed upon acceptable solvent.NOTE 6If water was found in the MPK,
30、 the weight of the MPK is tobe determined and recorded as Wsolvent2.10.4.11 Seal vial.10.4.12 Shake the sealed vial well to mix.10.4.13 Place vial in heating port and start the oven to runfor a period of 1 hour with air flow at 80 ml/min.10.4.14 Start the Karl Fischer Apparatus to determine totalper
31、cent water (Wwt).NOTE 7If water was found in the MPK, then operator must includeweight of MPK (Wsolvent2) in the denominator of total water calculation.10.4.15 Remove vial from the reaction port, place in adesiccant chamber to allow to cool to room temperature.10.4.16 Weigh the vial with the residue
32、 in and record as(Wnvc).10.4.17 Run a duplicate determination, steps 10.4.1 10.4.15, average the results.11. Calculations11.1 Percent Cure Water:Wwc5 Wwt2 Wws(1)11.2 Volatile content:Volatile content 5 Wv5S1 2FWnvc2 Wt!W12 W2!GD3100 (2)11.3 Adjusted water percent if MPK contained water:Adjusted wate
33、r5 (3)FW12 W2!1Wsolvent2! 3Wwt! 2 Wsolvent23Wwater!W12 W2!G12. Report12.1 Report the following information:12.1.1 All data determined from the test and all calculatedvalues.13. Precision and Bias5,613.1 PrecisionThe precision of this test method is basedon an interlaboratory study of Test Method D72
34、45, conductedin 2008. Analytical results in this study were obtained from sixlaboratories, testing six different materials, for Total Water andTotal Volatiles, run according to the standard in that theaverage of the duplicate was reported as a single individualdetermination. All participating labora
35、tories were asked toreport a duplicate test for each material. Practice E691 wasfollowed for the design and analysis of the data.13.1.1 Repeatability Limit (r)Two test results obtainedwithin one laboratory shall be judged not equivalent if theydiffer by more than the “r” value for that material. “r”
36、istheinterval representing the critical difference between two test5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D01-1140. ContactASTM CustomerService at serviceastm.org.6Supporting data have been filed at ASTM International H
37、eadquarters and maybe obtained by requesting Research Report RR:D01-1145. ContactASTM CustomerService at serviceastm.org.TABLE 1 Total Water (% by weight)NOTE 1This includes the water of polymerization and free water in the samples.Material AverageARepeatabilityStandardDeviationReproducibilityStanda
38、rdDeviationRepeatabilityLimitReproducibilityLimitXsrsRrRA 15.97 0.45 0.52 1.27 1.45B 8.35 0.13 0.69 0.35 1.93C 8.95 0.16 0.46 0.45 1.29D 10.64 0.34 0.77 0.95 2.14E 3.53 0.15 0.78 0.42 2.19F 12.46 0.48 1.35 1.33 3.78AThe average of the laboratories calculated averages.TABLE 2 Total Volatiles (% by we
39、ight)Material AverageARepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitXsrsRrRA 25.59 1.01 3.89 2.82 10.88B 31.09 0.76 1.56 2.13 4.37C 28.49 0.88 2.37 2.47 6.64D 31.11 0.65 3.65 1.82 10.23E 39.81 0.43 2.61 1.21 7.32F 39.29 1.07 1.78 2.99 4.97AThe av
40、erage of the laboratories calculated averages.D7245 09 (2014)3results for the same material, obtained by the same operatorusing the same equipment on the same day in the samelaboratory.13.1.1.1 Repeatability limits are listed in Table 1 and Table2.13.1.2 Reproducibility Limit (R)Two test results sha
41、ll bejudged not equivalent if they differ by more than the “R” valuefor that material; “R” is the interval representing the criticaldifference between two test results for the same material,obtained by different operators using different equipment indifferent laboratories.13.1.2.1 Reproducibility li
42、mits are listed in Table 1 andTable 2.13.1.3 The above terms (repeatability limit and reproduc-ibility limit) are used as specified in Practice E177.13.1.4 The repeatability limit and the reproducibility limitshould be considered as general guides, and the associatedprobability of 95 % as only a rou
43、gh indicator of what can beexpected.13.2 BiasAt the time of the study, there was no acceptedreference material suitable for determining the bias for this testmethod, therefore no statement on bias is being made.13.3 The precision statement was determined through sta-tistical examination of 144 data
44、points, from six laboratories,on six materials. The six materials tested were identified as thefollowing:Material A: Very low molecular weight phenolic resin, no solvent inthe sampleMaterial B: Solvent borne phenolic coating containing 55 % low-medium molecular weight phenolic resinMaterial C: Solve
45、nt borne phenolic coating containing 25 % lowmolecular weight phenolic resin and 25 % of very lowmolecular weight phenolic resin (material A)Material D: Solvent borne coating containing 60 % high molecularweight phenolic resinMaterial E: Solvent borne phenolic coating with 55 % very highmolecular we
46、ight phenolic resinMaterial F: Solvent borne phenolic coating with 60 % very highmolecular weight phenolic resinNOTE 8All the phenolic resin systems are of the phenol formaldehyderesol type.13.4 To judge the equivalency of two test results, it isrecommended to choose the material closest in characte
47、risticsto the test material.14. Keywords14.1 condensation reaction; cure water; drying oven; KarlFischer; total water; VOC; volatile; volatile organic contentASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standa
48、rd. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewe
49、d every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM Interna
