1、Designation: D7232 06 (Reapproved 2012)D7232 06 (Reapproved 2016)Standard Test Method forRapid Determination of the Nonvolatile Content of Coatingsby Loss in Weight1This standard is issued under the fixed designation D7232; the number immediately following the designation indicates the year oforigin
2、al 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 used to obtain rapid determination of the wei
3、ght percent nonvolatile (solids) content via instrumentalloss in weight technology. It is not meant as a replacement for Test Method D2369.1.2 This test method is principally intended for quality control labs and manufacturing environments where previouslycharacterized materials will be tested repea
4、tedly for different batches or lots.1.3 This test method can be used for waterborne and solventborne resins, intermediates and finished paint products. This testmethod may not be applicable to all types of coatings.1.4 The values stated in SI units are to be regarded as the standard. The values give
5、n in parentheses are for information only.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and to determine the applicability of regulat
6、orylimitations prior to use.NOTE 1There is no similar or equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:2D16 Terminology for Paint, Related Coatings, Materials, and ApplicationsD2369 Test Method for Volatile Content of CoatingsE180 Practice for Determining the Precision of ASTM Me
7、thods for Analysis and Testing of Industrial and Specialty Chemicals(Withdrawn 2009)33. Terminology3.1 Definitions:3.1.1 The definitions used in this test method are in accordance with Terminology D16.3.1.2 nonvolatile content, nthe coating material that remains in the pan at the conclusion of the t
8、est.3.2 Definitions of Terms Specific to This Standard:3.2.1 flip and squish, na testing technique that may be used when the expected nonvolatile content is greater than 40 %, orwhen the sample is highly viscous and does not absorb well into the filter paper.3.2.1.1 DiscussionThe specimen is applied
9、 to the filter paper on the sample pan, the filter paper is “flipped” over and the specimen is then “squished”between the filter paper and the sample pan in order to more uniformly distribute the specimen. In addition, use of this techniqueforces the glass fibers of the filter paper into the specime
10、n, helping to create pathways for volatiles release from the specimen andavoiding incomplete volatiles removal due to “skinning over” of the sample material.1 This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct
11、 responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved June 1, 2012Dec. 1, 2016. Published July 2012December 2016. Originally approved in 2006. Last previous edition approved in 20062012 asD7232 06. 06 (2012). DOI: 10.1520/D7232-06R12.10.152
12、0/D7232-06R16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical
13、standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM
14、recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.2 lif
15、t, nthe result of convection currents created during the heating of the specimen that raises the sample pan off of itssupport and falsely indicates a weight loss.3.2.2.1 DiscussionThis effect is compensated for by the use of an algorithm that is applied to the digital data.3.2.3 syringe tare, na tes
16、ting technique that may be used when the expected nonvolatile content is less than 40 %, or whenthe sample is highly volatile and tends to evaporate rapidly.3.2.3.1 DiscussionThe specimen weight is determined using an external balance by calculating the difference between the syringe weight before(i
17、nitial weight) and after (final weight) the specimen is applied to the pan. This difference between initial and final weight is theactual weight of specimen (see 10.2), and is used to minimize error due to rapid change of the specimen weight after addition toa heated sample pan.4. Summary of Test Me
18、thod4.1 The specimen is spread onto a sample pan that is supported on a balance in a heating chamber that has been preheated andequilibrated to the specified idle temperature. It is then heated to the specified test temperature to vaporize the volatiles. Theanalysis is completed when the indicated r
19、ate of weight loss falls below a rate specified in the test conditions. The total weightloss is calculated and reported as weight percent nonvolatiles. Both the analyzers balance and heater are calibrated withNIST-traceable standards to achieve precise and accurate results.4.2 Through adjustment of
20、the analyzers parameter settings, a set of optimal conditions is developed for each material type tomeasure the percent nonvolatiles. These optimal conditions are recorded and may be used for repeat testing of that material.5. Significance and Use5.1 This test method is intended for use as a rapid q
21、uality control, acceptance, and assessment test. Results are obtained in fiveto fifteen minutes on most materials. Since the instrument parameters are adjusted to produce the same results as Test MethodD2369, which takes over one hour to run, the time and effort expended on determining the optimal c
22、onditions for testing a coatingwith this instrumental method is valuable when numerous measurements are going to be made on different lots or batches of thesame material. Also, the automation of the measurement and the calculations should lead to fewer mistakes being made byless-trained operators.6.
23、 Apparatus6.1 Analyzer, containing:6.1.1 An oven capable of heating the sample to at least 225C.6.1.2 A balance capable of measuring to the nearest 0.0001 g.6.1.3 An electronic means of compensating for lift caused by convection currents created during testing.6.1.4 A processor that is capable of co
24、nverting the loss of weight to digital data.6.1.5 Digital display for presenting the digital data as weight percent nonvolatiles.6.2 Flat disposable pan, of aluminum alloy 3003, with smooth, uncoated, oil-free surface.6.3 Round glass-fiber filter paper, Grade 111.6.4 Syringe, 3 cc plastic slip-tip w
25、ithout needle but with cap, capable of dispensing specimen onto pan.6.5 Nitrogen compressed gas (N2) dry and oil-free.6.6 Compressed gas regulator(s), as needed to supply N2 from high-pressure sources to controlled delivery pressures that areappropriate for the apparatus.7. Reagents7.1 Sodium Tartra
26、te DihydrateACS certified reagent grade.8. Calibration and Standardization8.1 To maintain the integrity of the test results, the balance shall be calibrated using NIST-traceable weights and the heater shallbe calibrated using an NIST-traceable temperature calibration interface per the analyzer manuf
27、acturers guidelines.8.2 The calibration may be verified using sodium tartrate dihydrate, which has a theoretical water content of 15.66 %, with anacceptable result range of 15.61 to 15.71 %. Other procedures for materials with known theoretical water content are acceptablefor verification as specifi
28、ed by the analyzer manufacturer.D7232 06 (2016)28.3 Prepare the analyzer for use, select the preprogrammed instrument parameters for sodium tartrate dihydrate (or otherstandard material if applicable) and prepare analyzer for analysis as described in 9.1 using a flat pan without filter paper.8.4 Ini
29、tiate the test on the analyzer and follow the prompts for placing the specimen on the sample pan.8.5 Spread a thin, even layer of sodium tartrate dihydrate of appropriate specimen size onto the pan, then close lid to begin test.Specimen size shall be determined by analyzer manufacturer.8.6 If result
30、s are not within the acceptable range, first perform a temperature calibration, temperature calibration verification,and then a balance calibration to ensure proper analyzer performance. Retest with sodium tartrate dihydrate (or other standardmaterial as specified by the instrument manufacturer). If
31、 results still are not within the acceptable range, contact analyzermanufacturer.9. Procedure9.1 Preparing Analyzer for Sample Analysis:9.1.1 Place the analyzer on a flat, level surface.9.1.2 Establish N2 purge to the heating chamber per the instrument manufacturers instructions.9.1.3 Turn the analy
32、zer on and allow equilibration at the recommended idle temperature for balance calibration for 30 min.9.1.4 Perform balance calibration per the analyzer manufacturers instructions.9.2 Performing Sample Analysis:9.2.1 Program the analyzer with the desired test parameters, or select the suggested test
33、 conditions from Annex A1. See 9.3.1for determining the optimal conditions for testing a coating. See 9.3.5 for repeat testing of a coating using previously determinedoptimal conditions.9.2.2 Place a clean, flat sample pan with glass filter paper, rough side up, on the pan support and close the lid.
34、Allow the analyzerto equilibrate at the desired idle temperature.9.2.3 Ensure sample material is thoroughly mixed before drawing specimen into syringe.4 If using syringe tare technique (see3.2.3), proceed to step 9.2.4. If using flip and squish (see 3.2.1) technique, proceed to step 9.2.5.9.2.4 If s
35、yringe tare is used:9.2.4.1 Initiate the test on the analyzer and follow the prompts for placing the specimen on the sample pan.9.2.4.2 Draw sample material into the syringe, then wipe the syringe to ensure that no sample material remains on the exterior,then cap the syringe tip.9.2.4.3 Weigh the lo
36、aded syringe with cap on a balance and record the result. This is the initial weight.9.2.4.4 Quickly apply specimen to the filter paper on the pan by dispensing material from syringe onto the filter paper in a spiralpattern, then recap the syringe and close lid to begin test.9.2.4.5 Immediately weig
37、h the syringe and cap and record the result. This is the final weight. The difference between the initialand final weight of the syringe and cap is the actual specimen weight for the test, which is calculated as follows:WA 5WI 2WF (1)where:WA = actual weight of specimen to be entered into analyzer,W
38、I = initial weight of loaded syringe and cap, andWF = final weight of syringe and cap after dispensing specimen.9.2.5 If the flip and squish is used:9.2.5.1 Draw sample material into the syringe.9.2.5.2 Initiate the test on the analyzer and follow the prompts for placing the specimen on the sample p
39、an.9.2.5.3 Quickly apply specimen to the filter paper on the pan by dispensing material from syringe onto the filter paper in a spiralpattern.9.2.5.4 In rapid succession, remove the sample pan from the support, flip over the filter paper with tweezers and gently squishthe specimen between the filter
40、 paper and the sample pan. Place sample pan back onto pan support and close lid to begin test. Donot allow tweezers to come in contact with the specimen on the filter paper.9.2.6 At the end of the test, allow the analyzer to cool and remove the sample pan. If syringe tare was used, input the actuals
41、pecimen weight at the completion of the test to obtain the final result.9.2.7 Record the result as displayed in percent nonvolatiles.9.3 Determination of Optimal Test Conditions:NOTE 2When determining the optimal test conditions for a material, it is useful to have a calibrated forced-draft oven ava
42、ilable and test the materialin accordance with Test Method D2369.4 The specimen size will depend on the test conditions specified for a particular analyzer. See Table A1.1 in Annex A1 for suggested sample size for specified testconditions.D7232 06 (2016)39.3.1 Program the analyzer according to the c
43、onditions listed in Annex A1.3.9.3.2 To determine the optimum test temperature for a coating, run one series of tests on a single coating specimen that consistsof several consecutive programs that have been linked together. Each program is identical in its parameters except for thetemperature, which
44、 is progressively increased 5C on each successive program.NOTE 3For each test in the series, ensure that the ending weight of one test is used for the beginning weight of the subsequent test.NOTE 4Ensure that the program selected to run first corresponds to the lowest temperature in the linked serie
45、s.9.3.3 Record the result for each test in the linked series as the ratio of the ending weight to the beginning weight in percent bycalculating as follows:RN 5EN/BN! 3100# (2)where:RN = ratio of ending weight to beginning weight in percent for a given linked test N (to be plotted against temperature
46、),EN = ending weight for linked test N, andBN = beginning weight for linked test N.9.3.4 After the tests are completed, plot each linked test result, RN, versus temperature to make a curve as in Fig. 1.9.3.4.1 Most of the volatiles are vaporized in the temperature range from points 1 to 3.NOTE 5The
47、ratio of the ending weight to beginning weight increases with temperature for the specimen during the first few tests in linked series asthe higher temperatures evaporate more and more of the volatile content.9.3.4.2 Between points 3 and 5, the results approach 100 % (the ratio of ending weight to b
48、eginning approaches 1) and becomeconstant. Choose a temperature in this range as the optimum test temperature for that specimen material. A temperature in thisrange, where the RN value first becomes constant, ensures that there will be a total loss of volatiles from the specimen materialduring routi
49、ne analysis, and that the temperature is not excessively high.9.3.4.3 Beyond point 5, the results may begin to decrease. This trend is likely caused by decomposition of the sample.NOTE 6The region in the graph beyond point 5 may not necessarily be observed. The optimum temperature may be determined as described in step9.3.4.2 before a temperature sufficient to degrade the specimen is reached.9.3.5 After the optimal test temperature has been determined, adjust other appropriate parameters as needed to optimizecorrelation with results from an analysis by D
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