1、Designation: D 4026 06Standard Test Method forRubber LatexStyrene-Butadiene CopolymerDetermination of Residual Styrene1This standard is issued under the fixed designation D 4026; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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. Scope1.1 This test method covers the determination of the re-sidual styrene content of styrene butadiene (SBR) latex.
3、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 ofapproximately 5
4、0 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 this standard to
5、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:2D 4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Ca
6、rbon Black ManufacturingIndustriesE11 Specification for Wire Cloth and Sieves for TestingPurposesE 260 Practice for Packed Column Gas ChromatographyE 355 Practice for Gas Chromatography Terms and Rela-tionships3. Summary of Test Method3.1 A sample of latex is mixed with a wetting agent and aninterna
7、l 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 must be studi
8、ed 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 and vinyl tolue
9、ne 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-resolved, narrow,
10、 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 injection ports must
11、 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 knowledgeablein the techniques of gas chromatography. Practice E 260 an
12、d PracticeE 355, manufacturers literature, and standard texts on gas chromatogra-phy are especially helpful.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.11 on Chemical Analysis.Current edition approved Oct. 1, 2006. P
13、ublished October 2006. Originallyapproved in 1981. Last previous edition approved in 2002 as D 4026 87 (2002)e1.2For 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
14、standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.1.2 Equip the chromatograph with removable glass linersfor easy cleaning. Cleaning will be required when spuriouspeaks begin to appe
15、ar 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-resolvedstyrene and
16、 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 needle with a smallflam
17、e.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, that will accept the v
18、ials 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 tolueneand it shall sho
19、w 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 show turbidity whe
20、n 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 hazards.9. Samplin
21、g 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 the3The sole source of supply of nonionic wetting agent (Triton X100) known to thecommittee at this time is Rohm and Haas, Philadelphia, PA 19105. If yo
22、u are awareof alternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.TABLE 1 Parameters for the Gas ChromatographNOTEPackings and supports may
23、also be obtained from most companies that supply gas chromatographic supplies and equipment.Chromatograph AB C D EColumn:Glass X XStainless steel 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 % S
24、P 2100orOV-101/0.1 %Carbowax 150010 % OV 225C,B10 % Apiezon LE,B5 % SP 1200/1.7 % Bentone 34F,BSupport type SupelcoportA,BSupelcoport (1) ChromosorbW-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 heli
25、um 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, 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
26、 at this time is Supelco, Inc., Supelco Park, Bellefonte, PA 16823.BIf you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend
27、.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, Rockford, 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,
28、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 Sieve designations: No. 80 180 m, No. 100 150 m, No. 120 125 m.D4026062sample and test portion at his discretion. A necessary require-ment is that the test p
29、ortion 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 the analyst so chooses. In an
30、y 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-cm3volumetric flask and dilute
31、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 coagulates the latex, do not
32、 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, add5cm3of water (7.1),5cm3of
33、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).10.3.3 Label another bottle,
34、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 styrenesimilar to the expected content
35、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 correspond to the following st
36、yrene 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 response factor for styrene and
37、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 on a dry rubber basis is r
38、equired.)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 approximately the peak height
39、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 difficult, dilute with additional
40、Stock 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 an additional 1.0 cm3of Stoc
41、kSolution 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 will remain within the calibra
42、tionrange.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 this addition technique. See
43、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 styrene,C = area of the styrene
44、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 = response factor for styrene,C =
45、area of the styrene peak,M = mass of the latex in grams,D = area of the vinyl toluene peak, andT = 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)D4026063where:Md= mass of the dried sample in grams, andMw=
46、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 14,13.1.3 Whether the residual styren
47、e 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 D 4483. Refer to Practice D 4483 forterminology and other statistical calculation details.14.2 A Type 1 (in
48、terlaboratory) 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 the property or parameterin questi
49、on.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, that value tobe used in decisions abo
