1、Designation: D 7245 07e1Standard 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 c
2、ase 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.e1NOTEResearch report was added editorially in March 2008.1. Scope1.1 This test method is designed t
3、o measure total waterwhich includes cure water resulting from 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 wat
4、ercontent. This test method also permits for the simultaneousdetermination 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 me
5、thod 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
6、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 th
7、eresponsibility 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:3D 1193 Specification for Reagent WaterD 3925 Practice for Sampling Liquid Paints and
8、RelatedPigmented CoatingsD 3960 Practice for Determining Volatile 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 M
9、ethod3. 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
10、 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 titrati
11、on, 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, and Applica
12、tions and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis 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 1
13、1590. 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 p
14、age 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 water is treated as aVOC in other test methods, as these methods are unable toaccount for cure water.
15、 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 D 3960 to calculateVOC of the coating.6. Apparatus6.1 Glass VialA glass vial measuri
16、ng 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 vapo
17、rs 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, but with a cap, capable ofproperly dispensing the coating.7. Reagents47.1 Purity of ReagentReage
18、nt 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 Society wheresuch specifications are available. Other grades may be used,provided it is first ascerta
19、ined 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 Specification D 1193.7.3 Karl Fischer ReagentFor ketones.7.4 Methyl Propyl Ketone (MPK), or other appro
20、priatesolventTechnical 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 titration vessel.NOTE 1Equipment tested came equipped with a tapered plug de-signed for the tubing
21、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.8.2 The air-inlet port shall be attached to a source ofdesiccant-dried air or nitrogen.NOTE 3Testin
22、g 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 untilneeded.9. Calibration and Standardization9.1 Use the procedure specified in Test Method D 4017 forc
23、alibration 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 9.2.1.9.2.1 Weigh a sample of MPK, record as Wsolvent,tothenearest 0.1 mg.9.2.2 Perform Test Method D 4
24、017, 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 analyzed.NOTE 4Mixing time of 5 minutes has proven adequate for mostsamples.10.3 Should amount of cure w
25、ater 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 110 6 2C.10.4.2 Set the Airflow to 80 ml/min.10.4.3 Purge transfer line for a period of 5 minute
26、s 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 empty vial and septum to thenearest 0.0001 g and record weight (Wt).10.4.6 Using a syringe, draw a
27、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 Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of
28、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 OvenD724507e1210.4.9 Cap syringe and re-w
29、eigh, 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 tobe determined and recorded as Wsolvent2.10.4.11 Seal vial.10.4.12 Shake the sealed vial well to
30、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 water was found in the MPK, then operator must includeweight of MPK (Wsolvent2) in the denominator
31、 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).10.4.17 Run a duplicate determination, steps 10.4.1-10.4.15, average the results.11. Calculations11.
32、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!2Wsolvent23Wwater!W12W2!G12. Report12.1 Report the following information:12.1.1 All data determ
33、ined from the test and all calculatedvalues.13. Precision and Bias513.1 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 indi
34、vidualdeterminations or tests for each was recorded. Data from 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 on
35、e labo-ratory shall be judged not equivalent if they differ by 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
36、.13.1.2 Reproducibility LimitReproducibility cannot be es-timated 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
37、 can not be determined becauseno reference sample is available.14. Keywords14.1 condensation reaction; cure water; drying oven; KarlFischer; total water; VOC; volatile; volatile organic content5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Resear
38、ch Report RR: D011140.TABLE 1 Total VolatilesMaterial AverageRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitx sr sR r RSample A 43.57 2.47 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
39、 30.78 0.84 NA 2.35 NATABLE 2 Total WaterMaterial AverageRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitx sr sR r RSample A 16.23 0.83 NA 2.33 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
40、 0.66 NA 1.86 NAD724507e13ASTM 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 infrin
41、gement 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 standard
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43、 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).D724507e14
