1、Designation: D4026 06 (Reapproved 2012)Standard Test Method forRubber LatexStyrene-Butadiene CopolymerDetermination of Residual Styrene1This standard is issued under the fixed designation D4026; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f 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 covers the determination of the re-sidual styrene content of styrene butadien
3、e (SBR) latex. Thistest method is based upon direct injection of a diluted latex intoa gas chromatograph. The amount of residual styrene iscalculated using an internal standard technique.1.2 The range of residual styrene covered is approximately100 to 3000 mg/kg (ppm) with a lower detection limit of
4、approximately 50 mg/kg (ppm).1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of th
5、is standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. (For specific safetystatements, see Section 8.)2. Referenced Documents2.1 ASTM Standards:2D4483 Practice for Evaluating Precision for Test MethodStandards in the
6、 Rubber and Carbon Black ManufacturingIndustriesE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE260 Practice for Packed Column Gas ChromatographyE355 Practice for Gas Chromatography Terms and Rela-tionships3. Summary of Test Method3.1 A sample of latex is mixed with a wetting agent
7、and aninternal standard of vinyl toluene. It is then injected into a gaschromatograph equipped with a flame ionization detector. Theamount of residual styrene is determined by the internalstandard technique.4. Significance and Use4.1 The amount of residual styrene (unreacted styrene) in anSBR latex
8、must be studied from health, safety, economic, andenvironment viewpoints. This test method is useful in studyingthese aspects of residual styrene and also in research, devel-opment, and factory processing problems.5. Interferences5.1 Materials that interfere with the complete separation ofstyrene an
9、d vinyl toluene must be absent. Matrix effects(anything in the latex that affects the release of styrene or vinyltoluene, or both) may be minimized by the use of an additiontechnique.6. Apparatus6.1 Gas Chromatograph:6.1.1 Any gas chromatograph whose operating parametersand columns provide well-reso
10、lved, narrow, styrene and vinyltoluene peaks, free of interference, may be used. The chro-matograph must be equipped with a flame ionization detector(FID) and preferably with some means of electronic ormicroprocessor type of integration. Detectors must be operatedin the 200 to 300C range and injecti
11、on ports must be operatedin the 200 to 210C range.NOTE 1It is understood that the gas chromatograph will be operatedin accordance with the manufacturers instructions for optimum perfor-mance and that the equipment will be operated by persons knowledgeable1This test method is under the jurisdiction o
12、f ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.11 on Chemical Analysis.Current edition approved May 1, 2012. Published May 2012. Originallyapproved in 1981. Last previous edition approved in 2006 as D4026 06. DOI:10.1520/D4026-06R12.2For referenced ASTM standards,
13、 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 Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 194
14、28-2959, United States.in the techniques of gas chromatography. Practice E260 and PracticeE355, manufacturers literature, and standard texts on gas chromatographyare especially helpful.6.1.2 Equip the chromatograph with removable glass linersfor easy cleaning. Cleaning will be required when spurious
15、peaks begin to appear and usually after about 20 injections. Ifglass liners are not available, metal liners, packed with glasswool, may be used.6.2 Gas Chromatographic Columns, Packings, andProgramsAny column, packing, or program listed in Table 1is satisfactory, as long as it produces narrow, well-
16、resolvedstyrene and vinyl toluene peaks. Other columns, packings, andprograms may be used, as long as they satisfy these require-ments.6.3 Syringes, capable of delivering 1 mm3(1L).NOTE 2Syringes may be cleaned by drawing water into the syringebarrel, then ejecting it, while heating the syringe need
17、le with a smallflame.6.4 Pipets, capable of accurately delivering 0.1 cm3.6.5 Glass Vials, of 20-cm3capacity, equipped with self-sealing septa.6.6 Analytical Balance, capable of weighing to 60.1 mg.6.7 Ordinary Laboratory Glassware, necessary for carryingout this procedure.6.8 Mechanical Shaker, tha
18、t will accept the vials of 6.5.(Desirable, but not mandatory.)7. Reagents and Materials7.1 Deionized Water or equivalent.7.2 Nonionic Wetting Agent (isooctyl phenyl polyethoxyethanol).37.3 Styrene (p-tert butyl catechol, inhibited)There shallbe no chromatographic peaks that interfere with vinyl tolu
19、eneand it shall show no turbidity when mixed with methanol.7.4 Vinyl Toluene (polymerization grade28 % p-vinyltoluene and 72 % m-vinyl toluene) and pure o-vinyl toluene.Both chemicals elute from the chromatograph as one sharppeak and have the same response to the FID. Neither of thesechemicals shall
20、 show turbidity when mixed with methanol.8. Safety Precautions8.1 Special care should be exercised in the use of com-pressed gases required for the operation of the gas chromato-graph. Styrene and vinyl toluene should be handled in well-ventilated areas or in fume hoods, to minimize health andsafety
21、 hazards.3The sole source of supply of nonionic wetting agent (Triton X100) known to thecommittee at this time is Rohm and Haas, Philadelphia, PA 19105. If you are awareof alternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful con
22、sideration at a meeting of theresponsible technical committee,1which you may attend.TABLE 1 Parameters for the Gas ChromatographNOTEPackings and supports may also be obtained from most companies that supply gas chromatographic supplies and equipment.Chromatograph AB C D EColumn:Glass X XStainless st
23、eel X X XLength, cm 300 300 300 180 150Outside diameter, mm 6 3 3 3 6Inside diameter, mm 2 2Packed with 20 % SP 2100A,BorOV-101/0.1 %C,BCarbowax 1500D,B20 % SP 2100orOV-101/0.1 %Carbowax 150010 % OV 225C,B10 % Apiezon LE,B5 % SP 1200/1.7 % Bentone 34F,BSupport type SupelcoportA,BSupelcoport (1) Chro
24、mosorbW-HPG,B(2) ChromosorbP-NAWG,BChromosorb W SupelcoportMesh size, mH150/125 150/125 (1) 150/125(2) 180/150180/150 125Carrier gas helium helium helium helium heliumCarrier gas flow, cm3/min30 30 15 30 Detector, C 250 250 250 200 300Program:Initial, C 8090 8090 50 85Initial time, min 5 5 2 19Rate,
25、 C 8 8 16 50Final, C 120 120 135 150 165Isothermal No No Yes No NoAThe sole source of supply of the apparatus (SP 2100 and Supelcoport) known to the committee at this time is Supelco, Inc., Supelco Park, Bellefonte, PA 16823.BIf you are aware of alternative suppliers, please provide this information
26、 to ASTM International Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.CThe sole source of supply of the apparatus (OV-101 and 225) known to the committee at this time is Pierce Chemical Co., P.O. Box 117, Rockfo
27、rd, IL 61105.DThe sole source of supply of the apparatus (Carbowax 1500) known to the committee at this time is Union Carbide Corp., 270 Park Ave., New York, NY 10017.EThe sole source of supply of the apparatus (Apiezon L) known to the committee at this time is the James G. Biddle Co., Township Line
28、 Sieve designations: No. 80 180 m, No. 100 150 m, No. 120 125 m.D4026 06 (2012)29. Sampling and Selection of Test Portions9.1 Since the use of this test method may be required for anypurpose listed under Section 4, the analyst may choose thesample and test portion at his discretion. A necessary requ
29、ire-ment is that the test portion be as representative of the sampleas possible.10. Calibration10.1 For a series of analyses, sufficient stock and calibrationsolutions are made prior to test portion preparation. Theconcentrations of these solutions are tabulated as follows, butmay be different if th
30、e analyst so chooses. In any case, theexact concentrations of styrene and vinyl toluene must beknown.10.2 Stock Solutions:10.2.1 Stock Solution ADissolve 20 g of nonionic wettingagent (7.2) in 180 g of water (7.1).10.2.2 Stock Solution BWeigh approximately 250 6 0.1mg of styrene (7.3) into a 50-cm3v
31、olumetric flask and dilute tothe mark with Stock Solution A (10.2.1).10.2.3 Stock Solution CWeigh approximately 150 60.1 mg of vinyl toluene (7.4) into a 50-cm3volumetric flaskand dilute to the mark with Stock Solution A (10.2.1).NOTE 3In the subsequent analyses, if the addition of Stock SolutionA c
32、oagulates the latex, do not use. Substitute an equivalent volume ofwater (7.1). The use of this wetting agent is especially helpful in reducingplugging of the syringe needles and aids in the homogeneous dispersion ofadded styrene and vinyl toluene.10.3 Calibration MixturesTo each of four bottles, ad
33、d5cm3of water (7.1),5cm3of Stock Solution A (10.2.1).Proceed as follows:10.3.1 Label one bottle, D, and add 0.1 cm3of StockSolution B (10.2.2) and 1.0 cm3of Stock Solution C (10.2.3).10.3.2 Label another bottle, E, and add 0.4 cm3of StockSolution B (10.2.2) and 1.0 cm3of Stock Solution C (10.2.3).10
34、.3.3 Label another bottle, F, and add 0.6 cm3of StockSolution B (10.2.2) and 1.0 cm3of Stock Solution C (10.2.3).10.3.4 Label the last bottle, G, and add 1.5 cm3of StockSolution B (10.2.2) and 1.0 cm3of Stock Solution C (10.2.3).NOTE 4These calibration mixtures provide concentrations of styrenesimil
35、ar to the expected content in the latex and provide good dispersion ofthe styrene and vinyl toluene in the water phase. They also provideinternal standard concentrations in the same general range as styrene andcan be used to check response factors and detector linearity. Thecalibration standards cor
36、respond to the following styrene and vinyltoluene levels when mixed with5goflatex:Calibrationmixture Styrene, mg/kg Vinyl toluene, mg/kgD 100 600E 400 600F 600 600G 1500 60010.4 Response FactorsInject 1 mm3(1 L) of eachcalibration mixture D through G into the gas chromatographand determine the respo
37、nse factor for styrene and vinyltoluene. See the Annex for examples of response factorcalculations.11. Procedure11.1 Dry an aliquot of the sample latex to constant mass at|La105C. Calculate the total solids according to 12.3. (Thetotal solids content of the latex must be known if the residualstyrene
38、 on a dry rubber basis is required.)11.2 Accurately weigh approximately5goflatex to60.1 mg into a sample vial (6.5); then add 5.0 cm3of StockSolution A (10.2.1) and 1.0 cm3of Stock Solution C (10.2.3).NOTE 5It has been observed that adjusting the internal standardcontent to give a peak height of app
39、roximately the peak height of thestyrene in the sample, improves quantitative recovery.11.3 Agitate the vial for 5 min, either manually or mechani-cally.11.4 Inject 1 mm3(1 L) of this solution into the gaschromatograph and obtain the area of the styrene and vinyltoluene peaks. If injection is diffic
40、ult, dilute with additionalStock Solution A (10.2.1) or water (7.1).11.5 Check for matrix effects periodically according to11.5.1 and 11.5.2. (Adverse matrix effects have not beenobserved in most latex systems.)11.5.1 Repeat 11.2 for test portion preparation; then add 0.4cm3of Stock Solution B and a
41、n additional 1.0 cm3of StockSolution C. Continue as in 11.3 and 11.4. This preparation willcontain added styrene at 400 mg/kg (ppm) and additional vinyltoluene at 600 mg/kg (ppm). If the analyst so desires, addi-tional vinyl toluene need not be added, provided the styreneand vinyl toluene ratios wil
42、l remain within the calibrationrange.11.5.2 Calculate according to 12.1 for residual styrene. Ifthe results indicate that the matrix does affect these results (anincrease of residual styrene by three times the standarddeviation over that found in 11.2 through 11.4), the latex mustbe analyzed with th
43、is addition technique. See the Annex forsample calculation.12. Calculations12.1 Calculate the residual styrene on an as-received, wet,basis as follows:Residual styrene, mg/kg ppm!5A 3 B 3 C 3 1000/M 3 D!(1)where:A = milligrams of vinyl toluene added as internal standard,B = response factor for styre
44、ne,C = area of the styrene peak,M = mass of the latex in grams, andD = area of the vinyl toluene peak.12.2 Calculate the residual styrene on the dry rubber asfollows:Residual styrene, mg/kg ppm!5A 3 B 3 C 3 1000/M 3 T! 3 D!(2)where:A = milligrams of vinyl toluene added as internal standard,B = respo
45、nse factor for styrene,C = area of the styrene peak,M = mass of the latex in grams,D = area of the vinyl toluene peak, andD4026 06 (2012)3T = decimal equivalent of the percent total solids.12.3 Calculate the total solids (T) of the sample as follows:Total solids, % 5 Md3 100/Mw! (3)where:Md= mass of
46、 the dried sample in grams, andMw= mass of the wet latex in grams.13. Report13.1 The report shall contain the following information:13.1.1 Full identification of the sample and date of analysis,13.1.2 Average residual styrene from two determinations,that fall within the precision found in Section 14
47、,13.1.3 Whether the residual styrene has been calculated ona wet or dry basis, and13.1.4 Total solids content of the latex.14. Precision and Bias414.1 This precision and bias section has been prepared inaccordance with Practice D4483. Refer to Practice D4483 forterminology and other statistical calc
48、ulation details.14.2 A Type 1 (interlaboratory) precision was evaluated.Both repeatability and reproducibility are short term, a periodof a few days separates replicate test results.Atest result is theaverage value, as specified by this test method, obtained on twodeterminations or measurements of t
49、he property or parameterin question.14.3 Three different materials were used in the interlabora-tory program, these were tested in five laboratories on twodifferent days.14.4 The results of the precision calculations for repeatabil-ity and reproducibility are given in Table 2, in ascending orderof material average or level, for each of the materials evalu-ated.14.5 The precision of this test method may be expressed inthe format of the following statements which use what is calledan “appropriate value” of r, R, (r), or ( R), that is, t
