1、Designation: D 2124 99 (Reapproved 2004)Standard Test Method forAnalysis of Components in Poly(Vinyl Chloride) CompoundsUsing an Infrared Spectrophotometric Technique1This standard is issued under the fixed designation D 2124; the number immediately following the designation indicates the year ofori
2、ginal adoption or, in the case 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.1. Scope*1.1 This test method provides for the identification ofcertain r
3、esins, plasticizers, stabilizers, and fillers in poly(vinylchloride) (PVC) compounds by an infrared spectrophotometrictechnique. In many cases, individual components may bemeasured quantitatively. Complementary procedures, such aschromatographic and other separations, will be necessary toseparate sp
4、ecific components and extend the applications ofthis test method. Other instrumental test methods, such asoptical emission or X-ray spectroscopic methods, may yieldcomplementary information which may allow more completeor, in some cases, easier measurement of the components. Theresin components cove
5、red in this test method are listed in theappendix.1.2 PVC formulations are too varied to be covered ad-equately by a single test method. Using the following testmethod, many compounds may be separated into resins,plasticizers, stabilizers, and fillers. A number of componentscan be quantitatively mea
6、sured. Many more can be identifiedand their concentrations estimated. By the use of preparedstandards, one may determine the usefulness and accuracy ofthe test method for specific PVC formulations. This testmethod is applicable for the resin components listed in theappendix and for other components
7、having similar chemicalcompositions and solubility characteristics. This test methodcan lead to error in cases where the nature of the componentsis not known.1.3 The values stated in SI units are to be regarded as thestandard. The values in brackets are given for information only.1.4 This standard d
8、oes 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.NOTE 1There is no similar or equiv
9、alent ISO standard.2. Referenced Documents2.1 ASTM Standards:2E 131 Terminology Relating to Molecular SpectroscopyE 168 Practices for General Techniques of Infrared Quanti-tative AnalysisE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 275 Practice for Describing and Measu
10、ring Performanceof Ultraviolet, Visible, and Near Infrared Spectrophotom-eters3. Terminology3.1 Definitions:3.1.1 For definitions related to the material on infraredspectroscopy, refer to Terminology E 131.4. Summary of Test Method4.1 The PVC compound is solvent-extracted in order toseparate the pla
11、sticizer from the compound. The resin isdissolved from the remaining compound and the inorganicfillers and stabilizers separated by centrifuging. By this tech-nique, the compound is separated into (1) plasticizers, (2) resin,and (3) inorganic stabilizers and fillers. Each may be individu-ally analyz
12、ed by an infrared technique to identify and measurethe components.5. Significance and Use5.1 PVC compounds are used in a wide variety of productsand hence they are formulated to provide a wide range ofphysical properties. The physical properties required in acompound depend upon the product in which
13、 it is used. Theseproperties are largely determined by the type, quantity, andquality of the compounding ingredients. The analytical testmethod described below makes use of infrared spectrophotom-etry for the qualitative or quantitative determination, or both, ofmany of these ingredients in PVC comp
14、ounds. This testmethod may be used for a variety of applications including1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analytical Methods(Section D20.70.08).Current edition approved July 1, 2004. Published Jul
15、y 2004. Originally approvedin 1962. Last previous edition approved in 1999 as D 2124 - 99e1.2For 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 S
16、ummary page onthe ASTM website.1*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.process control, raw material acceptance, product evaluation,and determination of change
17、s in composition resulting fromenvironmental testing.5.2 This test method is directly applicable only to thosecomponents listed in the appendix and to those componentswhich are known to be similar in chemical composition and insolubility characteristics to the chemicals listed in the appen-dix.6. Ap
18、paratus6.1 Initial Sample PreparationUse any of the followingapparatus, depending on shape and size of sample, for reducingsolid samples to small particle sizes:6.1.1 Pencil Sharpener or grater and a cold box or con-tainer capable of maintaining at least the temperature of solidcarbon dioxide.6.1.2
19、Grinding Wheel, coarse.6.1.3 Microtome.6.1.4 Grinding or Cutting Mills, commercial, for example, aWiley mill (for samples larger than 1 g).6.2 Soxhlet Extraction Apparatus:6.2.1 For 0.5 and 1.0-g samples, use an extraction apparatuswith a 150-mL flask and a 27 by 100-mm thimble.6.2.2 For 0.2-g sampl
20、es, use an extraction apparatus with a30-mL flask and a 10 by 50-mm thimble.6.3 Mold and Press for KBr PelletsA mold assemblycapable of pelletizing a 12.7-mm 12-in. minimum diameterpellet under vacuum and a press capable of exerting pressuresof at least 140 MPa 20 000 psi are required to press clear
21、 KBrpellets.6.4 Infrared SpectrophotometerThe spectral region from4000 to 650 cm1(2.5 to 15 m) is used. Refer to PracticeE 275, with particular emphasis on Sections 5 and 14 relatingto resolution and spectral slit width measurements. An ultimateresolving power (1)3of at least 1.5 cm1at 850 cm1(0.02
22、mat 12 m) is satisfactory. The suitability of the instrumentshould be proven in the users laboratory. Demountable cells,1.0-mm liquid cells, and a KBr pellet holder are the accessoriesused.6.5 Infrared Spectrophotometer, Fourier Transform (FT-IR),capable of attaining a 4 wave number resolution.7. Re
23、agents7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grad
24、es may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 Alumina, absorption.7.3 Carbon Disulfide (CS2).7.4 Ether, anhydrous.7.5 Potassium Bromide, (KBr) infrared quality.7.6 Tetrachloroeth
25、ane, technical.7.7 Tetrahydrofuran (stabilized with 0.1 % hydroquinone).8. Component Separations8.1 Initial Sample PreparationAny test method that willincrease the surface area of a sample sufficiently to permitcomplete plasticizer extraction in a reasonable time is satisfac-tory. PVC compounds as r
26、eceived are usually in the form ofpowders, granules, slabs, or offshaped pieces. Powders may beused directly. Thin sheets, 0.02 to 0.05-mm thick, molded fromindividual granules may be used. Granules may be pressed intoslabs. Slabs or appropriately shaped pieces may be treated byone of the following
27、techniques:8.1.1 Buffing on a coarse grinding wheel,8.1.2 Cooling the sample with solid carbon dioxide andgrinding the brittle sample in a clean pencil sharpener or on agrater or clean file, or8.1.3 Shaving thin slices from the sample with a microtome.8.2 Plasticizer ExtractionWeigh to 60.2 mg appro
28、xi-mately1goffineparticle size sample into a 27 by 100-mmpaper extraction thimble. Place the thimble in a jacketedSoxhlet apparatus fitted with a tared 150-mL flask, and extractwith 120 mL of ethyl ether for 6 h (Note 2). Remove the tared150-mL flask, containing the ethyl ether and the extractedplas
29、ticizer, from the jacketed Soxhlet apparatus and gently heatto boil off the ethyl ether. Place the flask in an evacuateddesiccator for a minimum of1htoremove the last traces ofethyl ether. Weigh to 60.2 mg the flask containing theextracted plasticizers. Calculate the percentage of plasticizersin the
30、 PVC sample as follows:plasticizers, % 5weight of extracted plasticizers 3 100weight of PVC sample8.2.1 Keep the plasticizers for infrared identification ordetermination (8.4).NOTE 2Organometallic or organic stabilizer, if present, may partiallyor wholly separate from either the plasticizer or resin
31、 components andshould be considered when examining these compounds.8.3 Separation of Stabilizers and FillersEmpty the resin,stabilizers, and fillers remaining in the extraction thimble intoa 50-mL beaker. Add 20 mL of tetrachloroethane and heat thesample gently until the resin has dissolved. Wash th
32、e contentsof the beaker quantitatively into a tared 50-mL centrifuge tubewith 20 mL of tetrahydrofuran (which has been previouslypassed through a 150 by 12.7-mm 6 by12-in. diameteralumina absorption column to remove hydroquinone), swirl tomix, and centrifuge for 30 min. Decant the resin solution and
33、reserve for infrared analysis. Wash the residue remaining in thetared centrifuge tube with 20 mL of tetrahydrofuran andcentrifuge again for 30 min. Decant the solution containing theremaining resin. Repeat the operation. Dry the tared centrifugetube containing the stabilizer and filler in an oven at
34、 110C for1 h, cool, weigh, and calculate the percentage of inorganicstabilizer and filler as follows:3The boldface numbers in parentheses refer to the list of references at the end ofthis test method.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington,
35、DC. For suggestions on the testing of 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.D 2124 99 (2004)2
36、inorganic stabilizer and filler, % 5weight of stabilizer and filler 3 100weight of PVC sample8.3.1 Keep the stabilizer and filler for infrared analysis.Usually carbon black and color pigments are included in thisportion.8.4 ResinCalculate the percentage of resin by difference(100 minus the total per
37、cent of plasticizers, stabilizers, andfillers).9. Infrared Analysis of Extracted Plasticizers9.1 The extracted plasticizers may be run on the infraredspectrophotometer as liquid films for identification or in CS2solution for quantitative determinations.9.2 Identification of PlasticizersMost plastici
38、zers forPVC compounds are liquid at room temperature. A fewsecondary plasticizers may be solid but would be suspended ordissolved in primary plasticizers. A demountable cell withNaCl windows and a 0.025-mm spacer usually suffices to givea strong plasticizer spectrum (1). Scan the spectrum from 4000c
39、m1to 650 cm1(2.5 to 15 m). By reference to a collectionof plasticizer spectra the plasticizers in the sample may beidentified (2, 3, 4, 5, 6, 7, 8). With experience, rough estimatesof concentrations may be made to enable preparation ofmatching standards for quantitative analysis.9.3 Quantitative Ana
40、lysis of PlasticizersThe variety ofplasticizers and their possible combinations in PVC com-pounds is extensive. It is impossible to specify a singleprocedure that determines quantitatively all plasticizers withequal precision and bias. The following procedure is useful fora number of plasticizers an
41、d their combinations, particularly ifeither dioctyl phthalate or tricresyl phosphate is the primaryplasticizer. The user should decide whether the efficiency,precision, and bias of the procedure is satisfactory for a specificcombination of plasticizers to be analyzed.9.3.1 Weigh 60 6 0.2 mg of extra
42、cted plasticizer (from 8.2)into a 25-mL Erlenmeyer flask equipped with a glass stopper;add 20.00 mL of CS2to dissolve the plasticizers. Take care toavoid loss of solvent by keeping the Erlenmeyer flask stop-pered when possible. Run the resultant 3.00-mg/mL plasticizersolution on the infrared spectro
43、photometer (9) in a 1.0-mmliquid cell. Run a compensating 1.0-mm liquid cell or avariable path cell suitably adjusted, filled with CS2in thereference beam. After proper cleaning and drying of the samplecell, run an equivalent blank of CS2in the sample cell versusthe reference cell.9.3.2 A chart pres
44、entation on absorbance versus frequency(wavelength) paper of 20 cm/100 cm1for frequency and 18cm for zero to 1.0 absorbance range is satisfactory. However,other chart presentations may be used. For dioctyl phthalateand tricresyl phosphate the spectra ranges from 1800 to 1650cm1(5.4 to 6.1 m) and fro
45、m 1345 to 1090 cm1(7.4 to 9.2m) are useful. Dioctyl phthalate bands at 1725 cm1(5.80m), 1270 cm1(7.87 m), and 1121 cm1(8.92 m), andtricresyl phosphate band at 1191 cm1(8.4 m) are satisfactory.The dioctyl phthalate band chosen will depend, in part, onsecondary plasticizer interferences. Choice of ban
46、ds for otherplasticizers is left to the discretion of the user. At the analyticalband frequency (wavelength) chosen, absorbances for thesample spectrum (As+ Ab) and the blank spectrum (Ab) aremeasured. Net absorbance due to sample component Asis(As+ Ab)Ab.9.3.3 Prepare plasticizer standards by disso
47、lving the pureplasticizers of interest in CS2to give a series of standardsolutions covering the 3.0 to 0.5-mg/mL range for eachplasticizer. Run these standard plasticizer solutions underconditions identical to those under which the samples are runto obtain the net absorbances of the components at a
48、series ofconcentrations. Plot Beers law curves of net absorbancesversus concentrations in milligrams per millilitre for eachcomponent. All quantitative manipulations shall be in accor-dance with Practices E 168.9.3.4 Use the net absorbance of a specific plasticizer inconjunction with the appropriate
49、 Beers law curve to determinethe concentration in milligrams per millilitre.9.3.5 Calculate the percentage of plasticizer in the PVCcompound as follows:specific plasticizer, % 5 AB/3W! 3 100where:A = concentration of plasticizer, mg/mL,B = total weight of extracted plasticizers, mg, andW = weight of PVC sample, mg.10. Direct Infrared Determination of Plasticizers10.1 The use of this procedure usually presupposes that acomplete formulation analysis is not required and that theplasticizers to be determined are known.10.2 Weigh 0.25 g (60.25
