1、Designation: D5594 18aStandard Test Method forDetermination of the Vinyl Acetate Content of Ethylene-VinylAcetate (EVA) Copolymers by Fourier Transform InfraredSpectroscopy (FT-IR)1This standard is issued under the fixed designation D5594; the number immediately following the designation indicates t
2、he year oforiginal 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. Scope*1.1 This test method covers infrared procedures for
3、deter-mining the vinyl acetate content of EVA copolymers usingpressed films (Procedure A) or molded plaques (Procedure B)and internal corrections for sample thickness.1.2 This test method is applicable to the analysis of EVAcopolymers containing 0.5 to 55 % vinyl acetate except asspecified in 1.3.1.
4、3 Talc interferes with the 1020 cm1vinyl acetate band.Resins containing 5 % vinyl acetate and talc are excludedfrom the scope of this test method.1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are provided forinformation purposes only.1.5 This st
5、andard 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 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary s
6、tatements are given in Section 8.NOTE 1There is no known ISO equivalent to this standard.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards
7、, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E131 Terminology Relating to Molecular SpectroscopyE168 Practices for General Techniques of Infrared Quanti-tative AnalysisE177 Practice for Use
8、of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodIEEE/ASTM SI-10 Use of the International System of Units(SI): The Modem Metric SystemE691 Practice for Conducting an Interlaboratory Study toDetermine th
9、e Precision of a Test Method2.2 ISO Standard:ISO 8985 PlasticsEthylene/Vinyl Acetate CopolymerThermoplasticsDetermination of Vinyl Acetate33. Terminology3.1 Definitions:3.1.1 Units, symbols, and abbreviations used in this testmethod appear in Terminology E131 or IEEE/ASTM SI-10.3.2 Abbreviations:3.2
10、.1 EVAethylene-vinyl acetate copolymer.3.2.2 PTFEtetrafluorethylene polymer.3.2.3 FT-IRFourier transform infrared.4. Summary of Test Method4.1 The vinyl acetate content is measured using infraredabsorption band at 1020 cm1(0.5 to 5 % vinyl acetate) or 609cm1(5 to 55 % vinyl acetate).4.2 Sample thick
11、ness is measured internally using an ethyl-ene infrared absorption band at 720 cm1(28 to 55 % vinylacetate), 2020 cm1(0.5 to 28 % vinyl acetate), or 4250 cm1(5 to 28 % vinyl acetate).4.3 Regression analysis is performed on vinyl acetate/ethylene ratios versus known vinyl acetate contents for EVAcopo
12、lymer standards. The resulting equation is used to calcu-late the vinyl acetate content for subsequent EVA copolymersamples.1This test method is under the jurisdiction ofASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analytical Methods.Current edition approv
13、ed Nov. 1, 2018. Published November 2018. Originallyapproved in 1994. Last previous edition approved in 2018 as D5594 - 18. DOI:10.1520/D5594-18A.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards
14、 volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM Internat
15、ional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Gui
16、des and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15. Significance and Use5.1 Properties of EVA copolymers are affected by theamount of vinyl acetate incorporated in the copolymer: Thistest method provides a means to determine the vinyl acetat
17、elevel in copolymer samples.5.2 Before proceeding with this test method, referenceshould be made to the specification of the material being tested.Any test specimen preparation, conditioning, dimensions, ortesting parameters, or a combination thereof, covered in thematerials specification shall take
18、 precedence over those men-tioned in this test method. If there are no materialspecifications, then the default conditions apply.6. Apparatus6.1 Fourier Transform Infrared (FT-IR) Spectrophotometer,equipped with a detector, which gives a linear response overthe desired concentration range, is capabl
19、e of 4-cm2resolution(nominal), and is able to scan from 4400 to 450 cm1.NOTE 2ADTGS detector has been found suitable for this application.6.2 Hot Plate, (Sample Preparation Procedure A only).6.3 Microscope Slides, (Sample Preparation Procedure Aonly).6.4 Laboratory Press, capable of at least 9 000 k
20、g (20 000lb) 150C (300F), (Sample Preparation Procedure B only).6.5 Backing Plates, steel or aluminum (Sample PreparationProcedure B only).6.6 Brass Shim Stock (Roll), 50 to 150 m (2 to 6 mil) thickand 150 mm (6 in.) wide (Sample Preparation Procedure Bonly).6.7 Polyester Sheet, or fiberglass impreg
21、nated PTFE cloth(Sample Preparation Procedure B only).6.8 PTFE Film (Sample Preparation Procedure B, resinscontaining 40 % vinyl acetate only).6.9 Templates, (mold) with 150 150 mm (6 6 in.) piecesof paper or brass shim stock (item 6.6) containing cavities of asize and shape appropriate for the samp
22、le holders used, and, ifapplicable, sheets of items 6.7 and 6.8 (Sample PreparationProcedure B only).6.10 Cooling Block, steel or aluminum, at least 150 150mm (6 6 in.), approximately 25 mm (1 in.) thick, channeledfor cooling water (Sample Preparation Procedure B only).7. Materials7.1 EVA copolymer
23、standards containing nominal vinylacetate concentrations of 0.5 to 55 %, by weight.7.2 Dry ice (Sample Preparation B Procedure A only).8. Hazards8.1 Care shall be taken to avoid burns when handlingmicroscope slides on the hot-plate (Sample Preparation Proce-dure A), and gloves shall be worn when pla
24、ques are preparedusing a heated press (Sample Preparation Procedure B).8.2 Care also shall be taken to avoid breaking the micro-scope slides while removing the pressed polymer film.8.3 Care shall be taken to avoid burns when handling dryice.9. Specimen Preparation9.1 Procedure A:9.1.1 Control the ho
25、t-plate temperature at 250 6 10C.9.1.2 Place a microscope slide, containing a fraction of thesample pellet, on the hot-plate.9.1.3 Cover the sample with another slide and press with awooden pestle. Use film circular motions to press a uniformfilm.9.1.4 Remove the microscope slide from the hot-plate
26、andquench the pressed polymer film by dipping the two slides intoa beaker of cold water. Remove the film and blot dry with anabsorbent towel.9.1.5 Absorption maxima, measured on film produced bythis procedure, shall not exceed 1.5 absorbance units for eitherof the analytical bands used.9.2 Procedure
27、 B:NOTE 3Omit 9.2.1 to 9.2.11 for analysis of blown film.9.2.1 Select a brass or paper mold with a thickness appro-priate to the vinyl acetate content of the sample.The absorptionmaxima of the vinyl acetate and ethylene bands measured onthe plaque are not to exceed 1.5 absorbance units.NOTE 4To meet
28、 the absorbance requirement specified in 9.2.1 it willbe necessary to vary the mold thickness as the vinyl acetate contentchanges. The mold thickness required typically will be between 50 and150 m (2 to 6 mil).9.2.2 Place a polyester sheet (or fiberglass impregnatedPTFE cloth) followed by a brass or
29、 paper mold on a backingplate.NOTE 5For resins with vinyl acetate content 40 %, a PTFE filmshould be placed on top of the brass mold, or, if using a paper mold, underthe paper.9.2.3 Place a quantity of sample, appropriate to the thick-ness of the mold used, in the center of each opening in themold.
30、Do not overfill the mold openings.NOTE 6If flashing occurs, the brass mold and backing plates can becleaned with a nylon scrubbing pad.9.2.4 Place another piece of polyester sheet (or fiberglassimpregnated PTFE cloth) and a backing plate on top of thesample.NOTE 7For resins with vinyl acetate conten
31、t 40 %, a PTFE filmshould be placed over the sample before the polyester sheet (or fiberglassimpregnated PTFE cloth).9.2.5 Place the resulting “sandwich” in the press with theplatens heated at 150 to 175C.9.2.6 Close the press until the top platen barely touches thetop plate and leave for sufficient
32、 time to permit the sample tosoften and outgas.NOTE 8Acceptable plaques, free of gas bubbles, have been obtainedwhen the sample is allowed to soften for 3 min.9.2.7 Close the press completely and apply at least 9 000 kg(20 000 lb) force for approximately 1 min.9.2.8 Cool the “sandwich” to room tempe
33、rature, release thepressure, and remove the “sandwich” from the press.D5594 18a29.2.9 In cases where the press does not have coolingcapability or where sample throughput needs to be increased,the following alternative to 9.2.8 may be used. The “sandwich”is removed from the press hot and placed on a
34、metal coolingblock through which cold water is circulated.Amass of at least4 kg (9 lb) is placed on top to the “sandwich” while it cools toroom temperature.9.2.10 For resins with vinyl acetate content 40 %, separatethe backing plates and remove the plaques from the mold.9.2.11 For resins with vinyl
35、acetate content 40 %, place the“sandwich” on dry ice for at least 15 s before separating thebacking plate, polyester sheet (or fiberglass impregnated PTFEcloth), and the PTFE film from the plaque.9.2.12 Select plaques that are clear and of uniform thicknessfor the FT-IR analysis.10. Calibration10.1
36、Record the open beam background spectrum from4400 to 450 cm1at a nominal resolution of 4 cm1.10.2 Place a standard EVA copolymer film (plaque), pre-pared as described in 9.1 or 9.2, in the sample beam of theFT-IR spectrometer.10.3 Record the infrared spectrum from 4400 to 450 cm1ata nominal resoluti
37、on of 4 cm1. The signal-to-noise ratio, S/N,should be acceptable for the desired precision. A typical EVAcopolymer spectrum (9.0 % vinyl acetate) is shown in Fig. 1.10.4 Ratio the sample spectrum to the background spectrumand convert the results to absorbance.10.5 Measure the area of one vinyl aceta
38、te band and oneethylene band selected from the choices given in Table 1.Absorbance maxima for the analytical bands chosen are not toexceed 1.5 absorbance units.10.6 Draw a baseline tangent to the absorption minima oneither side of each peak. Determine the area of each peak abovethe baseline.10.7 Cal
39、culate the vinyl acetate/ethylene area ratio for theappropriate data reduction procedure defined in 12.1.10.7.1 For linear regression analysis:r 5 Ava/Aet(1)10.7.2 For nonlinear regression analysis:4R 5 Ava/Ava1Aet! (2)where:Ava= Area of vinyl acetate band, andAet= Area of ethylene band.10.8 Repeat
40、10.2 through 10.7.2 for each standard EVAcopolymer film (plaque).10.9 A minimum of five standards shall be used for thelinear regression of the 0.5 to 5.0 % vinyl acetate range. Thenumber of standards used for the nonlinear regression of eitherthe 5.0 to 28 % or 28 to 55 % vinyl acetate ranges shall
41、 not beless than six.10.10 The standards must cover the full range of vinylacetates to be analyzed. Extrapolation is not permitted.11. Procedure11.1 Prepare samples as described in 9.1 for films or 9.2 forplaques.11.2 Record the open beam background spectrum from4400 to 450 cm1at a nominal resolutio
42、n of 4 cm1.11.3 Place a sample film (plaque) in the sample beam of theFT-IR spectrometer.11.4 Record the infrared spectrum from 4400 to 450 cm1ata nominal resolution of 4 cm1. The signal-to-noise ratio, S/N,should be acceptable for the desired precision.11.5 Ratio the sample spectrum to the backgrou
43、nd spectrumand convert the result to absorbance.11.6 Measure the area of one vinyl acetate and one ethyleneband selected from the options given in Table 1. Absorbancemaxima for the analytical bands chosen are not to exceed 1.5absorbance units.11.7 Draw a baseline tangent to the absorption minima one
44、ither side of each peak. Determine the area of each peak abovethe baseline.11.8 Calculate the vinyl acetate to ethylene area ratio asspecified in 10.7.12. Calculation12.1 Regression Analysis:12.1.1 For vinyl acetate standards between 0.5 and 5.0 %,use linear regression analysis to determine the cali
45、brationequation of the data obtained in 10.7 and 10.8.12.1.2 For vinyl acetate standards covering the range 5.0 to28 % or 28 to 55 %, use nonlinear regression analysis, of thedata obtained in 10.7 and 10.8, to determine an equation of theform:4Cole, K. C., Pellerius, T. E., D, M. M., and Paroli, R.
46、M., “NewApproach toQuantitative Analysis of Two-Component Polymer Systems by InfraredSpectroscopy,” Applied Spectroscopy, Vol 50, No. 6, June 1996, pp. 774780.FIG. 1 FT-IR Spectrum of EVA Copolymer Standard (4.8 % VinylAcetate) Analyzed by Procedure BD5594 18a3VA, wt% 5 a1b 3R!11c 3R!(3)where:a, b,
47、and c are regression coefficients.12.2 Enter the sample area ratio from 11.8 into the appro-priate regression equation from 12.1 to calculate the weightpercent vinyl acetate.13. Report13.1 Report the following information:13.1.1 Complete identification of sample,13.1.2 Analytical bands used, and13.1
48、.3 Percent vinyl acetate.14. Precision and Bias514.1 The precision of this test method is based on aninterlaboratory study of ASTM D5594, Standard Test Methodfor Determination of the Vinyl Acetate Content of Ethylene-Vinyl Acetate (EVA) Copolymers by Fourier Transform Infra-red Spectroscopy (FT-IR),
49、 conducted in 2012. Five laboratoriesparticipated in this study. Each of the labs reported threereplicate test results for seven different sample concentrations,at two different wavelengths. Every “test result” reportedrepresents an individual determination. Practice E691 hasfollowed for the design and analysis of the data; the details aregiven in ASTM Research Report No. D20-1272.14.1.1 Repeatability (r)The difference between repetitiveresults obtained by the same operator in a given laboratoryapplying the same test method with
