1、Designation: D 7245 07Standard 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 (e) 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 fro
3、m 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 simultaneou
4、sdetermination 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 2
5、0 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 vesse
6、l.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 ap
7、pro-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 Vol
8、atile Organic Com-pound (VOC) Content of Paints and Related CoatingsD 4017 Test Method for Water in Paints and Paint Materialsby Karl Fischer MethodE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 cure water, nwater
9、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
10、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 D 4017, from total water, the percent of cure
11、 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 toaccount for cure water. This test metho
12、d 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 D 3960 to calculateVOC of the coating.6. Apparatus6.1 Glass VialA glass vial measuring 22 mm in diam
13、eter,38 mm in height having a capacity of 6 ml capable of beingsealed with a TFE-fluorocarbon septum.1This 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
14、 of Paints and Paint Materials.Current edition approved Feb. 1, 2007. Published March 2007.2Round-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 instrumen
15、ts.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.1Copyright ASTM International, 100 Barr Harbor Drive, PO B
16、ox C700, West Conshohocken, PA 19428-2959, United States.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.
17、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, but with a cap, capable ofproperly dispensing the coating.7. Reagents47.1 Purity of ReagentReagent grade chemicals shall beused in all tests unless otherwis
18、e indicated; it is intended thatall reagents conform to the specifications of the committee onAnalytical Reagents of 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 permi
19、t use.7.2 Purity of WaterUnless otherwise indicated referencesto water shall be understood to mean reagent grade conformingto type II of Specification D 1193.7.3 Karl Fischer ReagentFor ketones.7.4 Methyl Propyl Ketone (MPK), or other appropriatesolventTechnical Grade.8. Preparation of Apparatus8.1
20、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 titration 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 Fis
21、cher unit.NOTE 2Transfer line should be insulated to avoid condensation ofvapors in the line. The use of a heated transfer 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
22、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 untilneeded.9. Calibration and Standardization9.1 Use the procedure specified in Test Method D 4017 forcalibration and standardization of the Karl Fischer apparatus
23、.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 9.2.1.9.2.1 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.
24、Procedure10.1 Take a representative sample of the liquid coating inaccordance with Practice D 3925.10.2 Thoroughly mix the 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
25、 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 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
26、empty sealed vial served this purpose.10.4.4 Pretitrate contents of the Karl Fischer titration vesselto endpoint.10.4.5 Weigh 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
27、 0.0001 g and record (W1).10.4.8 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
28、 MPK, 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 tot
29、alpercent water (Wwt).NOTE 7If water was found in the MPK, then operator must includeweight of MPK (Wsolvent2) in the denominator of total water calculation.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reage
30、nts 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 OvenD724507210.4.15 Remove vial from the react
31、ion 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).10.4.17 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:Vol
32、atile 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!2Wsolvent23Wwater!W12W2!G12. Report12.1 Report the following information:12.1.1 All data determined from the test and all calculatedvalues.13. Precision and
33、Bias13.1 PrecisionThe precision of this test method is basedon a single laboratory study of Test Method D 7245, conductedin 2005. The laboratory tested five materials for two differentanalyses, Total Volatiles and Total Water. Three individualdeterminations or tests for each was recorded. Data from
34、thispreliminary study is listed in Table 1 and Table 2 under therepeatability. This data was calculated using Practice E 691.This data will be updated upon completion of round robintesting.13.1.1 RepeatabilityTwo tests obtained within one labo-ratory shall be judged not equivalent if they differ by
35、more thanthe “r” value for that material. “r” is the interval representingthe critical difference between two test results for the samematerial, obtained by the same operator using the sameequipment on the same day in the same laboratory.13.1.2 Reproducibility LimitReproducibility cannot be es-timat
36、ed from this study, as data was collected from only onelaboratory. Round robin testing of this test method will providenecessary information for reproducibility. This data will beavailable on or before June 2008.13.2 BiasThe bias on this can not be determined becauseno reference sample is available.
37、14. Keywords14.1 condensation reaction; cure water; drying oven; KarlFischer; total water; VOC; volatile; volatile organic contentTABLE 1 Total VolatilesMaterial AverageRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitx sr sR r RSample A 43.57 2.47
38、NA 6.91 NASample B 26.80 0.11 NA 0.31 NASample C 31.42 0.32 NA 0.91 NASample D 31.57 0.60 NA 1.67 NASample E 30.78 0.84 NA 2.35 NATABLE 2 Total WaterMaterial AverageRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitx sr sR r RSample A 16.23 0.83 NA 2
39、.33 NASample B 17.13 0.80 NA 2.23 NASample C 9.43 0.14 NA 0.38 NASample D 11.48 0.46 NA 1.30 NASample E 8.73 0.66 NA 1.86 NAD7245073ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard
40、 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 reviewed every five years andif n
41、ot 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
42、 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 copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D7245074
