1、Designation: D3314 02 (Reapproved 2012)Standard Test Method forRubberChemical Analysis for Polystyrene Blocks In SBR(Styrene-Butadiene Rubber) and Styrene-ReinforcedLatices1This standard is issued under the fixed designation D3314; the number immediately following the designation indicates the year
2、oforiginal adoption or, in the case of 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 longpolystyr
3、ene blocks in SBR rubbers and styrene-reinforcedlatices.1.2 Percent block styrene content may be determined in therange from 1 to 100 %.1.3 This test method is intended for use on gel-free poly-mers, but it may be used on polymers containing gel, if it hasbeen proven that gel does not interfere.1.4
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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazar
5、dstatements, see Section 7.2. Referenced Documents2.1 ASTM Standards:2D1076 Specification for RubberConcentrated, AmmoniaPreserved, Creamed, and Centrifuged Natural LatexD1416 Test Methods for Rubber from Synthetic SourcesChemical Analysis3D4483 Practice for Evaluating Precision for Test MethodStand
6、ards in the Rubber and Carbon Black ManufacturingIndustriesE145 Specification for Gravity-Convection and Forced-Ventilation Ovens3. Summary of Test Method3.1 The test method is based upon oxidative cleavage of theethylenic bonds in the block copolymer by treating a 1,2-dichlorobenzene solution of th
7、e polymer with tertiary butylhydroperoxide (2-methyl-2-hydroperoxypropane) with os-mium tetroxide catalyst. The saturated portions of the polymer,which contain no ethylenic bonds, remain unattacked. Thesmall fragments (low molecular weight aldehydes) and thelow-molecular weight polystyrene fragments
8、 from scissionswithin the random copolymer block are soluble in methylalcohol, whereas the detached high-molecular weight polysty-rene from the styrene homopolymer block is insoluble inalcohol. It is therefore possible to separate the high-molecularweight polystyrene, which constitutes the homopolym
9、er block,from the polymer solution.4. Significance and Use4.1 This test method is suitable for manufacturing control,development, and research studies.5. Apparatus5.1 Erlenmeyer Flask, or round-bottom flask for use withthe heating mantle, of 250-cm3capacity with ground-glassjoint. An iodine flask is
10、 also satisfactory.5.2 Air Condenser, for 5.1.5.3 Beaker, 600-cm3.5.4 Graduated Cylinder, 50-cm3.5.5 Pipet, 1-cm3.5.6 Buret, 100-cm3, for dispensing tertiary butyl hydroper-oxide.5.7 Thermometer, to 150C range.5.8 Crucible, Gooch-type, fritted-glass, medium-porosity,25 to 50-cm3size.5.9 Hot Plate, c
11、apable of operating to provide 120 to 130Cto boiling solution, or heating mantle for round-bottom flasksoperating in the same temperature range.5.10 Drying Oven, capable of controlling at 100C Type 1Boven in accordance with Specification E145.1This test method is under the jurisdiction of ASTM Commi
12、ttee 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 1974. Last previous edition approved in 2006 as D3314 02 (2006).DOI: 10.1520/D3314-02R12.2For referenced ASTM standards, visi
13、t 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.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1C
14、opyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Reagents6.1 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
15、Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 1,2-Dichlorobe
16、nzene.6.3 Methanol.6.4 Osmium Tetroxide (0.004 M Solution in Toluene 1 kg/m3(0.1 g/100 cm3)Protect the solution from light. Decompo-sition is indicated by formation of a black precipitate. Thevapors are highly toxic. Therefore, use due precaution inreagent preparation, use, and disposal. One cubic c
17、entimetre ofthis stock solution is needed for each analysis. In view of thetoxicity of the reagent, the amount of solution prepared shouldnot greatly exceed the number of determinations to be madeover a reasonable period of time, depending on the stability ofthe solution and the work load.6.5 Sulfur
18、ic Acid (density 1.84 Mg/m3)(H2SO4).6.6 Tertiary Butyl Hydroperoxide (2-Methyl-2-Hydroperoxypropane), approximately 70 % purity assay istypical.6.7 Toluene.7. Use of Osmium Tetroxide7.1 Precautions:7.1.1 Store osmium tetroxide ampules (maximum total of3 g) inside capped pipe or its equivalent.7.1.2
19、Persons working with osmium tetroxide or its solu-tions should wear rubber gloves, a rubber apron, and a faceshield or goggles.7.1.3 Keep solutions of osmium tetroxide (maximum of0.5 g) in unbreakable containers and store and use in the hood.The volume of air mechanically exhausted should be such th
20、atthe hood-face velocities are within acceptable limits (a recom-mended minimum of (0.5 m/s) 100 ft/min).7.1.4 Mark all containers of osmium tetroxide, whetherconcentrated or diluted with “DANGER” labels.7.1.5 Transfer all osmium tetroxide or its solutions to bedisposed of, to polyethylene bottles a
21、nd incinerate. Filtrates arecollected in a dump-can set aside for chlorinated solvents, andthe contents are also incinerated. Do not accumulate wastesolutions.7.2 Hazards:7.2.1 Osmium tetroxide is a yellow crystalline mass at roomtemperature. It can be hazardous in either its crystalline orvapor for
22、m. On contact with the skin or eyes, it producesirritation and if not removed immediately, may cause derma-titis and ulceration of the skin and intense conjunctivitis andcorneal ulceration to the eye. Inhalation of osmium tetroxidemay cause capillary bronchitis and dermatitis. Even smallamounts, if
23、inhaled over a considerable period, cause head-ache, insomnia, pharyngeal and laryngeal distress, and diges-tive disturbance. (WarningAnalysts must thoroughly famil-iarize themselves with a current Material safety data Sheet(MSDS) for osmium tetroxide.)7.2.2 The vapor has a pronounced acrid, chlorin
24、e-like odor,which should be taken as a warning of the toxic concentrationin the atmosphere, and personnel should immediately removeto an area of fresh air. The minimum perceptible concentrationis 0.02 g/m3of air. The threshold safety limit is 0.002 mg/m3of air. Therefore, it cannot be detected by od
25、or at the thresholdsafety limit. The melting point of the crystals is 56C and theboiling point at 100 kPa is 130C. However, it begins tosublime and distill well below the boiling point.8. Sampling8.1 If the sample is latex, prepare a dried film in accordancewith Specification D1076.8.2 If the sample
26、 is an oil-extended rubber, conduct an ETAextraction in accordance with Test Methods D1416.8.3 In all cases, use a random unhomogenized sample.9. Procedure9.1 For a sample containing less than 30 % block styrene,cut approximately 0.5 g of rubber weighed to the nearest0.1 mg into small pieces. Add th
27、e pieces to a 250-cm3Erlenmeyer flask (or round-bottom flask), to which 35 cm3of1,2-dichlorobenzene has been previously added. For rubberscontaining more than 30 % block styrene, use a 0.3-g speci-men.9.2 Fit an air condenser to the flask and heat it and itscontents to 120 6 5C, until the rubber dis
28、solves.9.3 Remove the flask from the hot plate or heating mantleand cool it just enough to stop refluxing. Separate the aircondenser from the flask, add 10 cm3of the tertiary butylhydroperoxide solution (see 6.6) and 1 cm3of the osmiumtetroxide solution (see 6.4). Replace the air condenser andcontin
29、ue heating the resulting solution at 100 to 120C for 12to 15 min. (Polystyrene is itself slowly degraded in thisprocess, therefore digestion time should be constant and notlengthy.)9.4 Remove the flask from the hot plate or heating mantle.When it has cooled so that it can be held without discomfort,
30、pour the solution slowly and with constant stirring into a600-cm3beaker containing 350 cm3of methanol to which 5drops of concentrated H2SO4has been added. Agitate theresulting mixture with a magnetic stirrer for 1 to 2 h, toflocculate the insoluble polystyrene.9.5 Quantitatively transfer, with the a
31、id of a rubber “police-man,” the precipitated polystyrene to a tared, medium-frittedGooch crucible. Wash the precipitated polystyrene copiouslywith methanol to remove all the 1,2-dichlorobenzene, then with100 cm3of hot water to remove surfactants and electrolytes.Finally, wash with 100 cm3of methano
32、l again.9.6 Dry the precipitate for2hat100C, cool in a desiccator,and weigh.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for Laborato
33、ryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D3314 02 (2012)210. Calculation10.1 Calculate the percent block styrene as follows:Block styrene, % 5 WA2 WB!/WC# 3 100 (1)where:WA= mass of
34、crucible + polystyrene precipitate, g,WB= mass of crucible, g, andWC= mass of sample, g.10.2 A test result is the average of two test determinations.11. Precision and Bias511.1 This precision and bias section has been prepared inaccordance with Practice D4483. Refer to Practice D4483 forterminology
35、and other statistical calculation details.11.2 A Type 1 (interlaboratory) precision was evaluated.Both repeatability and reproducibility are short term, a periodof a few days separates replicate test results. A test result is theaverage value as specified by this test method, obtained on twodetermin
36、ations or measurements of the property or parameterin question.11.3 Five different materials were used in the interlabora-tory program, these were tested in two laboratories on fourdifferent days.11.4 The results of the precision calculations for repeatabil-ity and reproducibility are given in Table
37、 1, in ascending orderof material average or level, for each of the materials evalu-ated.11.5 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
38、ut test results (obtained with this testmethod). The appropriate value is that value of r or Rassociated with a mean level in Table 1 closest to the meanlevel under consideration at any given time, for any givenmaterial in routine testing operations.11.6 RepeatabilityThe repeatability, r, of this te
39、st methodhas been established as the appropriate value for any parametertabulated in Table 1. Two single test results, obtained undernormal test method procedures, that differ by more than thistabulated r (for any given level) must be considered as derivedfrom different or nonidentical sample popula
40、tions.11.7 ReproducibilityThe reproducibility, R, of this testmethod has been established as the appropriate value tabulatedin Table 1. Two single test results obtained in two differentlaboratories, under normal test method procedures, that differby more than the tabulated R (for any given level) mu
41、st beconsidered to have come from different or nonidentical samplepopulations.11.8 Repeatability and reproducibility expressed as a per-centage of the mean level, (r) and (R), have equivalentapplication statements as above for r and R. For the (r) and (R)statements, the difference in the two single
42、test results isexpressed as a percentage of the arithmetic mean of the two testresults.11.9 BiasIn test method terminology, bias is the differ-ence between an average test value and the reference (or true)test property value. Reference values do not exist for this testmethod since the value (of the
43、test property) is exclusivelydefined by the test method. Bias, therefore, cannot be deter-mined.12. Keywords12.1 polystyrene; SBR; styrene-butadiene rubber5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D11-1001.TABLE 1 Type 1 P
44、recisionNOTESr= within laboratory standard deviation.r = repeatability (in measurement units).(r) = repeatability (in percent).SR= between laboratory standard.R = reproducibility (in measurement units).(R) = reproducibility (in percent).Material Mean Value, %Within Laboratories Between LaboratoriesS
45、rr (r)ASRR (R)A1 2.85 0.509 1.44 50.5 0.320 0.906 31.72 5.03 0.498 1.41 28.0 0.553 1.56 31.03 16.54 0.650 1.84 11.1 0.720 2.04 12.44 29.81 0.707 2.00 6.71 0.550 1.56 5.25 37.78 1.64 4.64 12.3 2.75 7.78 20.6ARelative precision, that is, for this test method a percent of a percentage.D3314 02 (2012)3A
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49、e on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D3314 02 (2012)4
