ASTM D2124-99(2004)
(Test Method)Standard Test Method for Analysis of Components in Poly(Vinyl Chloride) Compounds Using an Infrared Spectrophotometric Technique
Standard Test Method for Analysis of Components in Poly(Vinyl Chloride) Compounds Using an Infrared Spectrophotometric Technique
SIGNIFICANCE AND USE
PVC compounds are used in a wide variety of products and hence they are formulated to provide a wide range of physical properties. The physical properties required in a compound depend upon the product in which it is used. These properties are largely determined by the type, quantity, and quality of the compounding ingredients. The analytical test method described below makes use of infrared spectrophotometry for the qualitative or quantitative determination, or both, of many of these ingredients in PVC compounds. This test method may be used for a variety of applications including process control, raw material acceptance, product evaluation, and determination of changes in composition resulting from environmental testing.
This test method is directly applicable only to those components listed in the appendix and to those components which are known to be similar in chemical composition and in solubility characteristics to the chemicals listed in the appendix.
SCOPE
1.1 This test method provides for the identification of certain resins, plasticizers, stabilizers, and fillers in poly(vinyl chloride) (PVC) compounds by an infrared spectrophotometric technique. In many cases, individual components may be measured quantitatively. Complementary procedures, such as chromatographic and other separations, will be necessary to separate specific components and extend the applications of this test method. Other instrumental test methods, such as optical emission or X-ray spectroscopic methods, may yield complementary information which may allow more complete or, in some cases, easier measurement of the components. The resin components covered in this test method are listed in the appendix.
1.2 PVC formulations are too varied to be covered adequately by a single test method. Using the following test method, many compounds may be separated into resins, plasticizers, stabilizers, and fillers. A number of components can be quantitatively measured. Many more can be identified and their concentrations estimated. By the use of prepared standards, one may determine the usefulness and accuracy of the test method for specific PVC formulations. This test method is applicable for the resin components listed in the appendix and for other components having similar chemical compositions and solubility characteristics. This test method can lead to error in cases where the nature of the components is not known.
1.3 The values stated in SI units are to be regarded as the standard. The values in brackets are given for information only.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Note 1—There is no similar or equivalent ISO standard.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D2124–99 (Reapproved 2004)
Standard Test Method for
Analysis of Components in Poly(Vinyl Chloride) Compounds
Using an Infrared Spectrophotometric Technique
This standard is issued under the fixed designation D2124; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* 2. Referenced Documents
1.1 This test method provides for the identification of 2.1 ASTM Standards:
certain resins, plasticizers, stabilizers, and fillers in poly(vinyl E131 Terminology Relating to Molecular Spectroscopy
chloride)(PVC)compoundsbyaninfraredspectrophotometric E168 Practices for General Techniques of Infrared Quanti-
technique. In many cases, individual components may be tative Analysis
measured quantitatively. Complementary procedures, such as E177 Practice for Use of the Terms Precision and Bias in
chromatographic and other separations, will be necessary to ASTM Test Methods
separate specific components and extend the applications of E275 Practice for Describing and Measuring Performance
this test method. Other instrumental test methods, such as of Ultraviolet and Visible Spectrophotometers
optical emission or X-ray spectroscopic methods, may yield
3. Terminology
complementary information which may allow more complete
or, in some cases, easier measurement of the components. The 3.1 Definitions:
3.1.1 For definitions related to the material on infrared
resin components covered in this test method are listed in the
appendix. spectroscopy, refer to Terminology E131.
1.2 PVC formulations are too varied to be covered ad-
4. Summary of Test Method
equately by a single test method. Using the following test
4.1 The PVC compound is solvent-extracted in order to
method, many compounds may be separated into resins,
separate the plasticizer from the compound. The resin is
plasticizers, stabilizers, and fillers. A number of components
dissolved from the remaining compound and the inorganic
can be quantitatively measured. Many more can be identified
fillers and stabilizers separated by centrifuging. By this tech-
and their concentrations estimated. By the use of prepared
nique,thecompoundisseparatedinto(1)plasticizers,(2)resin,
standards, one may determine the usefulness and accuracy of
and (3) inorganic stabilizers and fillers. Each may be individu-
the test method for specific PVC formulations. This test
ally analyzed by an infrared technique to identify and measure
method is applicable for the resin components listed in the
the components.
appendix and for other components having similar chemical
compositions and solubility characteristics. This test method
5. Significance and Use
can lead to error in cases where the nature of the components
5.1 PVC compounds are used in a wide variety of products
is not known.
and hence they are formulated to provide a wide range of
1.3 The values stated in SI units are to be regarded as the
physical properties. The physical properties required in a
standard.Thevaluesinbracketsaregivenforinformationonly.
compound depend upon the product in which it is used. These
1.4 This standard does not purport to address all of the
properties are largely determined by the type, quantity, and
safety concerns, if any, associated with its use. It is the
quality of the compounding ingredients. The analytical test
responsibility of the user of this standard to establish appro-
methoddescribedbelowmakesuseofinfraredspectrophotom-
priate safety and health practices and determine the applica-
etryforthequalitativeorquantitativedetermination,orboth,of
bility of regulatory limitations prior to use.
many of these ingredients in PVC compounds. This test
NOTE 1—There is no similar or equivalent ISO standard.
method may be used for a variety of applications including
process control, raw material acceptance, product evaluation,
ThistestmethodisunderthejurisdictionofASTMCommitteeD20onPlastics
and is the direct responsibility of Subcommittee D20.70 on Analytical Methods
(Section D20.70.08). For referenced ASTM standards, visit the ASTM website, www.astm.org, or
CurrenteditionapprovedJuly1,2004.PublishedJuly2004.Originallyapproved contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
´1
in 1962. Last previous edition approved in 1999 as D2124-99 . DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D2124-99R04. the ASTM website.
*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.
D2124–99 (2004)
and determination of changes in composition resulting from 7.2 Alumina, absorption.
environmental testing. 7.3 Carbon Disulfide (CS ).
5.2 This test method is directly applicable only to those
7.4 Ether, anhydrous.
components listed in the appendix and to those components
7.5 Potassium Bromide, (KBr) infrared quality.
which are known to be similar in chemical composition and in
7.6 Tetrachloroethane, technical.
solubility characteristics to the chemicals listed in the appen-
7.7 Tetrahydrofuran (stabilized with 0.1% hydroquinone).
dix.
8. Component Separations
6. Apparatus
8.1 Initial Sample Preparation—Any test method that will
6.1 Initial Sample Preparation—Use any of the following
increase the surface area of a sample sufficiently to permit
apparatus,dependingonshapeandsizeofsample,forreducing
complete plasticizer extraction in a reasonable time is satisfac-
solid samples to small particle sizes:
tory. PVC compounds as received are usually in the form of
6.1.1 Pencil Sharpener or grater and a cold box or con-
powders, granules, slabs, or offshaped pieces. Powders may be
tainer capable of maintaining at least the temperature of solid
useddirectly.Thinsheets,0.02to0.05-mmthick,moldedfrom
carbon dioxide.
individualgranulesmaybeused.Granulesmaybepressedinto
6.1.2 Grinding Wheel, coarse.
slabs. Slabs or appropriately shaped pieces may be treated by
6.1.3 Microtome.
one of the following techniques:
6.1.4 Grinding or Cutting Mills,commercial,forexample,a
8.1.1 Buffing on a coarse grinding wheel,
Wiley mill (for samples larger than 1 g).
8.1.2 Cooling the sample with solid carbon dioxide and
6.2 Soxhlet Extraction Apparatus:
grinding the brittle sample in a clean pencil sharpener or on a
6.2.1 For0.5and1.0-gsamples,useanextractionapparatus
grater or clean file, or
with a 150-mL flask and a 27 by 100-mm thimble.
8.1.3 Shavingthinslicesfromthesamplewithamicrotome.
6.2.2 For 0.2-g samples, use an extraction apparatus with a
8.2 Plasticizer Extraction—Weigh to 60.2 mg approxi-
30-mL flask and a 10 by 50-mm thimble.
mately1goffine particle size sample into a 27 by 100-mm
6.3 Mold and Press for KBr Pellets—A mold assembly
paper extraction thimble. Place the thimble in a jacketed
capable of pelletizing a 12.7-mm [ ⁄2-in.] minimum diameter
Soxhlet apparatus fitted with a tared 150-mLflask, and extract
pellet under vacuum and a press capable of exerting pressures
with 120 mLof ethyl ether for6h(Note 2). Remove the tared
ofatleast140MPa[20000psi]arerequiredtopressclearKBr
150-mL flask, containing the ethyl ether and the extracted
pellets.
plasticizer,fromthejacketedSoxhletapparatusandgentlyheat
6.4 Infrared Spectrophotometer—The spectral region from
to boil off the ethyl ether. Place the flask in an evacuated
−1
4000 to 650 cm (2.5 to 15 µm) is used. Refer to Practice
desiccator for a minimum of1hto remove the last traces of
E275,withparticularemphasisonSections5and14relatingto
ethyl ether. Weigh to 60.2 mg the flask containing the
resolution and spectral slit width measurements. An ultimate
extracted plasticizers. Calculate the percentage of plasticizers
−1 −1
resolving power (1) of at least 1.5 cm at 850 cm (0.02 µm
in the PVC sample as follows:
at 12 µm) is satisfactory. The suitability of the instrument
weightofextractedplasticizers 3100
should be proven in the user’s laboratory. Demountable cells,
plasticizers,% 5
weightofPVCsample
1.0-mmliquidcells,andaKBrpelletholderaretheaccessories
used.
8.2.1 Keep the plasticizers for infrared identification or
6.5 Infrared Spectrophotometer, Fourier Transform (FT-IR), determination (8.4).
capable of attaining a 4 wave number resolution.
NOTE 2—Organometallic or organic stabilizer, if present, may partially
or wholly separate from either the plasticizer or resin components and
7. Reagents
should be considered when examining these compounds.
7.1 Purity of Reagents—Reagent grade chemicals shall be
8.3 Separation of Stabilizers and Fillers—Empty the resin,
used in all tests. Unless otherwise indicated, it is intended that
stabilizers, and fillers remaining in the extraction thimble into
all reagents shall conform to the specifications of the Commit-
a 50-mL beaker.Add 20 mL of tetrachloroethane and heat the
tee onAnalytical Reagents of theAmerican Chemical Society,
sample gently until the resin has dissolved. Wash the contents
where such specifications are available. Other grades may be
of the beaker quantitatively into a tared 50-mLcentrifuge tube
used, provided it is first ascertained that the reagent is of
with 20 mL of tetrahydrofuran (which has been previously
sufficiently high purity to permit its use without lessening the
passed through a 150 by 12.7-mm [6 by ⁄2-in.] diameter
accuracy of the determination.
alumina absorption column to remove hydroquinone), swirl to
mix, and centrifuge for 30 min. Decant the resin solution and
reserveforinfraredanalysis.Washtheresidueremaininginthe
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
tared centrifuge tube with 20 mL of tetrahydrofuran and
this test method.
centrifugeagainfor30min.Decantthesolutioncontainingthe
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
remaining resin. Repeat the operation. Dry the tared centrifuge
listed by the American Chemical Society, see Analar Standards for Laboratory
tube containing the stabilizer and filler in an oven at 110°C for
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
1 h, cool, weigh, and calculate the percentage of inorganic
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD. stabilizer and filler as follows:
D2124–99 (2004)
weightofstabilizerandfiller 3100
sample spectrum (A + A ) and the blank spectrum (A ) are
s b b
inorganicstabilizerandfiller,% 5
weightofPVCsample
measured. Net absorbance due to sample component A is
s
(A + A)− A .
8.3.1 Keep the stabilizer and filler for infrared analysis. s b b
9.3.3 Prepare plasticizer standards by dissolving the pure
Usually carbon black and color pigments are included in this
plasticizers of interest in CS to give a series of standard
portion.
solutions covering the 3.0 to 0.5-mg/mL range for each
8.4 Resin—Calculate the percentage of resin by difference
plasticizer. Run these standard plasticizer solutions under
(100 minus the total percent of plasticizers, stabilizers, and
conditions identical to those under which the samples are run
fillers).
to obtain the net absorbances of the components at a series of
concentrations. Plot Beer’s law curves of net absorbances
9. Infrared Analysis of Extracted Plasticizers
versus concentrations in milligrams per millilitre for each
9.1 The extracted plasticizers may be run on the infrared
component. All quantitative manipulations shall be in accor-
spectrophotometer as liquid films for identification or in CS
dance with Practices E168.
solution for quantitative determinations.
9.3.4 Use the net absorbance of a specific plasticizer in
9.2 Identification of Plasticizers—Most plasticizers for
conjunctionwiththeappropriateBeer’slawcurvetodetermine
PVC compounds are liquid at room temperature. A few
the concentration in milligrams per millilitre.
secondaryplasticizersmaybesolidbutwouldbesuspendedor
9.3.5 Calculate the percentage of plasticizer in the PVC
dissolved in primary plasticizers. A demountable cell with
compound as follows:
NaCl windows and a 0.025-mm spacer usually suffices to give
specificplasticizer,% 5 ~AB/3W! 3100
astrongplasticizerspectrum(1).Scanthespectrumfrom4000
−1 −1
cm to 650 cm (2.5 to 15 µm). By reference to a collection
where:
of plasticizer spectra the plasticizers in the sample may be
A = concentration of plasticizer, mg/mL,
identified (2, 3, 4, 5, 6, 7, 8).With experience, rough estimates
B = total weight of extracted plasticizers, mg, and
of concentrations may be made to enable preparation of
W = weight of PVC sample, mg.
matching standards for quantitative analysis.
10. Direct Infrared Determination of Plasticizers
9.3 Quantitative Analysis of Plasticizers—The variety of
plasticizers and their possible combinations in PVC com-
10.1 The use of this procedure usually presupposes that a
pounds is extensive. It is impossible to specify a single
complete formulation analysis is not required and that the
procedure that determines quantitatively all plasticizers with
plasticizers to be determined are known.
equal precision and bias.The following procedure is useful for
10.2 Weigh 0.25 g (60.25 mg) of fine particle size sample
a number of plasticizers and their combinations, particularly if
into a 10 by 50-mm extraction thimble. Place the thimble in a
either dioctyl phthalate or tricresyl phosphate is the primary
microSoxhletextractionapparatus.Extractfor6hwith20mL
plasticizer. The user should decide whether the efficiency,
ofCS .TransfertheCS containingtheextractedplasticizersto
2 2
precision,andbiasoftheprocedureissatisfactoryforaspecific
a25-mLvolumetricflask,dilutetothemarkwithCS ,andmix
combination of plasticizers to be analyzed.
thoroughly. Run this solution on the infrared spectrophotom-
9.3.1 Weigh60 60.2mgofextractedplasticizer(from8.2)
eter. Instrumental conditions and techniques, preparation of
into a 25-mL Erlenmeyer flask equipped with a glass stopper;
standards, and Beer’s law curves are the same as those
add 20.00 mL of CS to dissolve the plasticizers. Take care to
specified in 9.2.
avoid loss of solvent by keeping the Erlenmeyer flask stop-
10.3 Calculation—Calculate the percentage of a specific
pered when possible. Run the resultant 3.00-mg/mLplasticizer
plasticizer in the PVC compound as follows:
solution on the infrared spectrophotometer (9) in a 1.0-mm
specificplasticizer,% 5 ~25A/W! 3100
liquid cell. Run a compensating 1.0-mm liquid cell or a
variable path cell suitably adjusted, filled with CS in the where:
referenceb
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