1、Designation: D 7245 09Standard Test Method forMeasuring Total Water and Volatiles in Liquid CoatingsWhich Produce Cure Water Upon Heating1This standard is issued under the fixed designation D 7245; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e 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
3、 the heat inducedcondensation reaction of coatings. Cure water cannot bemeasured directly by Test Method D 4017. This task isaccomplished by measuring water content in the vaporsevolved during heating. This test method will yield total watercontent. This test method also permits for the simultaneous
4、determination of total volatile content. The results of this testmethod may be used to calculate VOC content. Although thistest method was designed for phenolic coatings, it can be usedwith other types of coatings.1.2 Materials used for method development and evaluationhad total water values from 20
5、 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
6、.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 app
7、ro-priate safety and health practices and to determine theapplicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3D 1193 Specification for Reagent WaterD 3925 Practice for Sampling Liquid Paints and RelatedPigmented CoatingsD 3960 Practice for Determining Vola
8、tile Organic Com-pound (VOC) Content of Paints and Related CoatingsD 4017 Test Method for Water in Paints and Paint Materialsby Karl Fischer MethodE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precisio
9、n 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 add
10、ed 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 Fi
11、scher titration, TestMethod D 4017, 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.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials
12、, and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved Feb. 1, 2009. Published April 2009. Originallyapproved in 2007. Last previous edition approved in 2007 as D 7245 - 071.2Round-robin collaborators used
13、 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.or
14、g. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Significance and Use5.1 In the determination of VOC, cure wate
15、r is treated as aVOC in other test methods, as these methods are unable toaccount 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
16、 in Practice D 3960 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 i
17、s 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 D 4017.6.5 SyringeMinimum of 1 ml but no more than 5 mlcapacity equipped without a needle,
18、 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 of the American Chemical Soci
19、ety 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 conformingto type II of Specif
20、ication D 1193.7.3 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 liquidin the Karl Fischer ti
21、tration vessel.NOTE 1Equipment tested came equipped with a tapered plug de-signed for the tubing to fit through and which was tapered to fit into theKarl Fischer unit.NOTE 2Transfer line should be insulated to avoid condensation ofvapors in the line. The use of a heated transfer line is preferred.8.
22、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 storing in a desiccator untilne
23、eded.9. Calibration and Standardization9.1 Use the procedure specified in Test Method D 4017 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 thesolvent, proceed to 9.2.1.
24、9.2.1 Weigh a sample of MPK, record as Wsolvent,tothenearest 0.1 mg.9.2.2 Perform Test Method D 4017, record the weight per-cent water results as Wwater.10. Procedure10.1 Take a representative sample of the liquid coating inaccordance with Practice D 3925.10.2 Thoroughly mix the sample to be analyze
25、d.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 D 4017 (Wws).10.4 Determine Total Water (Wwt) and Volatile content(Wv).10.4.1 Preheat the Drying oven to
26、 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 Weigh preconditioned em
27、pty 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).10.4.8 Transfer approximately 0.2 ml (0.3 g) of the sampleto the glass vial.4Reagent Chemicals, American Chemical Soc
28、iety Specifications , AmericanChemical Society, Washington, 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. Pharmacop
29、eial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Drying OvenD724509210.4.9 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, the weight of the MPK is to
30、be 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 totalpercent water (Wwt).NOTE 7If wa
31、ter 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 in and record as(Wnvc).10.4
32、.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 2FWnvc Wt!W1 W2!GD3 100 (2)11.3 Adjusted water percent if MPK contained water:Adjusted water 5 (3)FW12W2!1Wsolvent2!3Wwt
33、!2Wsolvent23Wwater!W12W2!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 D 7245, conductedin 2008. Analytical
34、 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 laboratories were asked toreport a dup
35、licate test for each material. Practice E 691 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”istheinterval representing the
36、critical difference between two testresults 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 shall bejudged not equivalent
37、 if they differ by more than the “R” valuefor that material; “R” is the interval representing the critical5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D011140.6Supporting data have been filed at ASTM International Headquarte
38、rs and maybe obtained by requesting Research Report RR: D011145.TABLE 1 Total Water (% by weight)NOTEThis includes the water of polymerization and free water in the samples.Material AverageARepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitx srsRrRA
39、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 weight)Material AverageARepeatabilityStandardDeviationReprod
40、ucibilityStandardDeviationRepeatabilityLimitReproducibilityLimitx srsRrRA 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 average of the laboratories calculated averages.D7245093dif
41、ference between two test results for the same material,obtained by different operators using different equipment indifferent laboratories.13.1.2.1 Reproducibility limits are listed in Table 1 andTable 2.13.1.3 The above terms (repeatability limit and reproduc-ibility limit) are used as specified in
42、Practice E 177.13.1.4 The repeatability limit and the reproducibility limitshould be considered as general guides, and the associatedprobability of 95 % as only a rough indicator of what can beexpected.13.2 BiasAt the time of the study, there was no acceptedreference material suitable for determinin
43、g 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 points, from six laboratories,on six materials. The six materials tested were identified as thefollowing:Material A: Very low molecula
44、r weight phenolic resin, no solvent in the sampleMaterial B: Solvent borne phenolic coating containing 55 % low-medium mo-lecular weight phenolic resinMaterial C: Solvent borne phenolic coating containing 25 % low molecularweight phenolic resin and 25 % of very low molecular weight phe-nolic resin (
45、material A)Material D: Solvent borne coating containing 60 % high molecular weight phe-nolic resinMaterial E: Solvent borne phenolic coating with 55 % very high molecularweight phenolic resinMaterial F: Solvent borne phenolic coating with 60 % very high molecularweight phenolic resinNOTE 8All the ph
46、enolic 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 characteristicsto the test material.14. Keywords14.1 condensation reaction; cure water; drying oven; KarlFischer; total water; VOC; vola
47、tile; volatile organic contentASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof in
48、fringement 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 reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this stan
49、dard 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 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple
