ASTM D5594-98

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 5594 – 98
Standard Test Method for
Determination of the Vinyl Acetate Content of Ethylene-Vinyl
Acetate (EVA) Copolymers by Fourier Transform Infrared
Spectroscopy (FT-IR)
This standard is issued under the fixed designation D 5594; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope * ISO 8985 Plastics—Ethylene/Vinyl Acetate Copolymer
,
4 5
Thermoplastics—Determination of Vinyl Acetate
1.1 This test method covers infrared procedures for deter-
mining the vinyl acetate content of EVA copolymers using
3. Terminology
pressed films (Procedure A) or molded plaques (Procedure B)
3.1 Definitions:
and internal corrections for sample thickness.
3.1.1 Units, symbols, and abbreviations used in this test
1.2 This test method is applicable to the analysis of EVA
method appear in Terminology E 131 or Practice E 380.
copolymers containing 0.5 to 55 % vinyl acetate except as
3.2 Abbreviations:
specified in 1.3.
−1 3.2.1 EVA—ethylene-vinyl acetate copolymer.
1.3 Talc interferes with the 1020 cm vinyl acetate band.
3.2.2 PTFE—tetrafluorethylene polymer.
Resins containing <5 % vinyl acetate and talc are excluded
3.2.3 FT-IR—Fourier transform infrared.
from the scope of this test method.
1.4 The values stated in SI units are to be regarded as the
4. Summary of Test Method
standard. The values given in parentheses are provided for
4.1 The vinyl acetate content is measured using infrared
information purposes only.
−1
absorption band at 1020 cm (0.5 to 5 % vinyl acetate) or 609
1.5 This standard does not purport to address all of the
−1
cm (5 to 55 % vinyl acetate).
safety concerns, if any, associated with its use. It is the
4.2 Sample thickness is measured internally using an ethyl-
responsibility of the user of this standard to establish appro-
−1
ene infrared absorption band at 720 cm (28 to 55 % vinyl
priate safety and health practices and determine the applica-
−1 −1
acetate), 2020 cm (0.5 to 28 % vinyl acetate), or 4250 cm (5
bility of regulatory limitations prior to use. Specific precau-
to 28 % vinyl acetate).
tionary statements are given in Section 8.
4.3 Regression analysis is performed on vinyl acetate/
NOTE 1—This test method is not equivalent to ISO 8985.
ethylene ratios versus known vinyl acetate contents for EVA
copolymer standards. The resulting equation is used to calcu-
2. Referenced Documents
late the vinyl acetate content for subsequent EVA copolymer
2.1 ASTM Standards:
samples.
E 131 Terminology Relating to Molecular Spectroscopy
E 168 Practices for General Techniques of Infrared Quanti- 5. Significance and Use
tative Analysis
5.1 Properties of EVA copolymers are affected by the
E 177 Practice for Use of the Terms Precision and Bias in
amount of vinyl acetate incorporated in the copolymer: This
ASTM Test Methods
test method provides a means to determine the vinyl acetate
E 380 Practice for Use of the International System of Units
level in copolymer samples.
(SI) (the Modernized Metric System)
5.2 Before proceeding with this test method, reference
E 691 Practice for Conducting an Interlaboratory Study to
should be made to the specification of the material being tested.
Determine the Precision of a Test Method
Any test specimen preparation, conditioning, dimensions, or
2.2 ISO Standard:
1 4
This test method is under the jurisdiction of ASTM Committee D-20 on Plastics Available from American National Standards Institute, 11 W. 42nd St., 13th
and is the direct responsibility of Subcommittee D20.70 on Analytical Methods. Floor, New York, NY 10036.
Current edition approved Nov. 10, 1998. Published January 1999. Originally Nicolet 20 S 3 B, available from Nicolet Instrument Corp., Analytical Divi-
e1
published as D 5594 – 94. Last previous edition D 5594 – 94 . sion, 5225 Verona Rd., Madison, WI 53711-4495, and Perkin Elmer 1760, a
Annual Book of ASTM Standards, Vol 03.06. registered trademark of Perkin-Elmer Corp., 761 Main Ave., Norwalk, CT 06859-
Annual Book of ASTM Standards, Vol 14.02. 0156, or equivalents, have been found suitable for this purpose.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 5594 – 98
testing parameters, or a combination thereof, covered in the 9.1.4 Remove the microscope slide from the hot-plate and
materials specification shall take precedence over those men- quench the pressed polymer film by dipping the two slides into
tioned in this test method. If there are no material specifica- a beaker of cold water. Remove the film and blot dry with an
tions, then the default conditions apply. absorbent towel.
9.1.5 Absorption maxima, measured on film produced by
6. Apparatus this procedure, shall not exceed 1.5 absorbance units for either
of the analytical bands used.
6.1 Fourier Transform Infrared (FT-IR) Spectrophotometer,
9.2 Procedure B:
equipped with a detector, which gives a linear response over
the desired concentration range, is capable of 4-cm resolution
NOTE 3—Omit 9.2.1 to 9.2.11 for analysis of blown film.
−1
(nominal), and is able to scan from 4400 to 450 cm .
9.2.1 Select a brass or paper mold with a thickness appro-
NOTE 2—A DTGS detector has been found suitable for this application.
priate to the vinyl acetate content of the sample. The absorption
6.2 Hot Plate, (Sample Preparation Procedure A only).
maxima of the vinyl acetate and ethylene bands measured on
6.3 Microscope Slides, (Sample Preparation Procedure A the plaque are not to exceed 1.5 absorbance units.
only).
NOTE 4—To meet the absorbance requirement specified in 9.2.1 it will
6.4 Laboratory Press, capable of at least 9 000 kg (20 000
be necessary to vary the mold thickness as the vinyl acetate content
lb) 150°C (300°F), (Sample Preparation Procedure B only).
changes. The mold thickness required typically will be between 50 and
6.5 Backing Plates, steel or aluminum (Sample Preparation
150 μm (2 to 6 mil).
Procedure B only).
9.2.2 Place a polyester sheet (or fiberglass impregnated
6.6 Brass Shim Stock (Roll), 50 to 150 μm (2 to 6 mil) thick
PTFE cloth) followed by a brass or paper mold on a backing
and 150 mm (6 in.) wide (Sample Preparation Procedure B
plate. For resins with vinyl acetate content $40 %, a PTFE
only).
film should be placed on top of the brass mold, or, if using a
6.7 Polyester Sheet, or fiberglass impregnated PTFE cloth
paper mold, under the paper.
(Sample Preparation Procedure B only).
9.2.3 Place a quantity of sample, appropriate to the thick-
6.8 PTFE Film (Sample Preparation Procedure B, resins
ness of the mold used, in the center of each opening in the
containing $40 % vinyl acetate only).
mold. Do not overfill the mold openings. If flashing occurs, the
6.9 Templates, (mold) with 150 3 150 mm (6 3 6 in.)
brass mold and backing plates can be cleaned with a nylon
pieces of paper or brass shim stock (item 6.6) containing
scrubbing pad.
cavities of a size and shape appropriate for the sample holders
9.2.4 Place another piece of polyester sheet (or fiberglass
used, and, if applicable, sheets of items 6.7 and 6.8 (Sample
impregnated PTFE cloth) and a backing plate on top of the
Preparation Procedure B only).
sample. For resins with vinyl acetate content $40 %, a PTFE
6.10 Cooling Block, steel or aluminum, at least 150 3 150
film should be placed over the sample before the polyester
mm (6 3 6 in.), approximately 25 mm (1 in.) thick, channeled
sheet (or fiberglass impregnated PTFE cloth).
for cooling water (Sample Preparation Procedure B only).
9.2.5 Place the resulting “sandwich” in the press with the
platens heated at 150 to 175°C.
7. Materials
9.2.6 Close the press until the top platen barely touches the
7.1 EVA copolymer standards containing nominal vinyl
top plate and leave for sufficient time to permit the sample to
acetate concentrations of 0.5 to 55 %, by weight.
soften and outgas.
7.2 Dry ice (Sample Preparation B Procedure A only).
NOTE 5—Acceptable plaques, free of gas bubbles, have been obtained
when the sample is allowed to soften for 3 min.
8. Hazards
8.1 Care should be taken to avoid burns when handling
9.2.7 Close the press completely and apply at least 9 000 kg
microscope slides on the hot-plate (Sample Preparation Proce-
(20 000 lb) force for approximately 1 min.
dure A), and gloves should be worn when plaques are prepared
9.2.8 Cool the “sandwich” to room temperature, release the
using a heated press (Sample Preparation Procedure B).
pressure, and remove the “sandwich” from the press.
8.2 Care also should be taken to avoid breaking the micro-
9.2.9 In cases where the press does not have cooling
scope slides while removing the pressed polymer film.
capability or where sample throughput needs to be increased,
8.3 Care should be taken to avoid burns when handling dry
the following alternative to 9.2.8 may be used. The “sandwich”
ice.
is removed from the press hot and placed on a metal cooling
block through which cold water is circulated. A mass of at least
9. Specimen Preparation
4 kg (9 lb) is placed on top to the “sandwich” while it cools to
room temperature.
9.1 Procedure A:
9.2.10 For resins with vinyl acetate content <40 %, separate
9.1.1 Control the hot-plate temperature at 250 6 10°C.
9.1.2 Place a microscope slide, containing a fraction of the the backing plates and remove the plaques from the mold.
sample pellet, on the hot-plate. 9.2.11 For resins with vinyl acetate content $40 %, place
9.1.3 Cover the sample with another slide and press with a the “sandwich” on dry ice for at least 15 s before separating the
wooden pestle. Use film circular motions to press a uniform backing plate, polyester sheet (or fiberglass impregnated PTFE
film. cloth), and the PTFE film from the plaque.
D 5594 – 98
9.2.12 Select plaques that are clear and of uniform thickness 10.9 A minimum of five standards shall be used for the
for the FT-IR analysis. linear regression of the 0.5 to 5.0 % vinyl acetate range
...