1、Designation: D4934 02 (Reapproved 2012)Standard Test Method forRubber Compounding Materials: 2-BenzothiazylSulfenamide AcceleratorsInsolubles1This standard is issued under the fixed designation D4934; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、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 a general procedure for thedetermination of insoluble impurities
3、 of sulfenamides in suit-able organic solvents.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibilit
4、y 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.2. Referenced Documents2.1 ASTM Standards:2D4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black Manu
5、facturingIndustries3. Summary of Test Method3.1 A specimen of sulfenamide is dissolved in a prescribedsolvent, stirred, and filtered through a crucible. The insolublecontent is calculated from the amount of residue.4. Significance and Use4.1 Sulfenamides can degrade in chemical purity and func-tiona
6、l performance, usually characterized by a drop in assay, arelease of free amine, and an increase in insolubles. This testmethod may be used as an indication of such degradation.4.2 Since MBTS (mercaptobenzothiazole disulfide) is aprimary degradation product of sulfenamides, the determina-tion of MBT
7、S is a means of assessing possible degradation ofsulfenamides. Insolubles are a means of mercaptobenzothiazyldisulfide (MBTS) content of the sulfenamide; MBTS is aprimary degradation product of sulfenamides. Amine salts ofmercaptobenzothiazole (MBT) may also be insoluble. How-ever, certain soluble s
8、pecies may also be generated duringsulfenamide degradation. Consequently, insolubles are not anabsolute measure of purity and can actually decrease withsulfenamide degradation.5. Apparatus5.1 Erlenmeyer Flask, 300 cm3.5.2 Sintered Glass Crucible, G4.5.3 Measuring Cylinder, 250 cm3.5.4 Magnetic Stirr
9、er.5.5 Watch Glass.5.6 Vacuum Flask.5.7 Explosion-proof, Vented Air Circulating Oven, capableof temperature regulation of 70 6 2C.5.8 Balance, analytical, with a sensitivity of 60.01 g.5.9 Washing Bottle.5.10 Sieve, 30 Mesh (U.S. Standard), or equivalent (forexample, 0.6 mm).6. Reagents6.1 Purity of
10、 ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.3Other grades may be used,provided it i
11、s first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.6.2 Methanol, analytical reagent.6.3 Cyclohexane, analytical reagent.7. Hazards7.1 Methanol and cyclohexane, with threshold limit values(TLVs) of 200 cm3/m3and 300
12、cm3/m3, respectively, and highflammability, should be handled with appropriate caution.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 May 1, 2012. Published July 2012. Or
13、iginally approvedin 1989. Last previous edition approved in 2006 as D4934 02 (2006). DOI:10.1520/D4934-02R12.2For 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 sta
14、ndards Document Summary page onthe ASTM website.3Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Pool
15、e, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.2 Good laboratory safety practices should be follo
16、wed inhandling all chemicals and carrying out manipulations.8. Sampling8.1 Sampling shall be at the discretion of the analyst toobtain as representative a sample as possible of the lot to betested.9. Procedure9.1 Solvents:9.1.1 MethanolUse for testing specimens ofN-cyclohexyl-2-benzothiazole sulfena
17、mide (CBS), N,N-diisopropyl-2-benzothiazyl sulfenamide (DIBS), 2(morpholi-nothio)benzothiazole (MBS), and N-tert-butyl-benzothiazolesulfenamide (TBBS).9.1.2 CyclohexaneUse for testing DCBS specimens.9.2 Grind approximately 10 g of a well-mixed lot sample sothat material passes through a 30-mesh (0.6
18、-mm) sieve.9.3 Transfer5gofthespecimen (W1), weighed to thenearest 0.01 g, to a 300-cm3Erlenmeyer flask. Using agraduated cylinder, add 250 cm3of methanol. In the case ofDCBS, use cyclohexane instead of methanol. Cover the flaskwith a watch glass and stir cold, on a magnetic stirrer, for 30min at 25
19、 6 5C.9.4 Filter the solution, with suction, through a clean, dry,preweighed (W2) sintered glass crucible. It is important thatduring filtration, the crucible is only half filled. Wash theErlenmeyer flask with 25 cm3of methanol, or in the case ofDCBS, with 25 cm3of cyclohexane. Filter the washings.9
20、.5 At the end of the filtration, remove the suction and washthe crucible two times with 25 cm3of methanol or, in the caseof DCBS, with 25 cm3of cyclohexane. Allow to stand for 2min and then suck the washings through quickly. When this hasbeen done, the walls of the crucible should be free fromresidu
21、e.9.6 Dry the crucible for 60 min in an oven maintained at70C.9.7 Cool to room temperature in a desiccator and obtain themass of the crucible plus insolubles to the nearest milligram(W3).10. Calculation10.1 Calculate the percent insoluble content, C, in percentas follows:C 5 W32 W2!/W1# 3 100(1)wher
22、e:W1= mass of sample, g,W2= mass of empty crucible, g, andW3= mass of crucible and insoluble material, g.11. Report11.1 Report the following information:11.1.1 The proper identification of the sample, and11.1.2 The results obtained from two individual determina-tions and their average reported to th
23、e nearest 0.01 %.12. Precision and Bias12.1 This precision and bias section has been prepared inaccordance with Practice D4483. Refer to Practice D4483 forterminology and other statistical calculation details.12.1.1 The precision results in this precision and biassection give an estimate of the prec
24、ision of this test methodwith the materials (rubbers) used in the particular interlabora-tory programs as described below. The precision parametersshould not be used for acceptance/rejection testing of anygroup of materials without documentation that they are appli-cable to those particular material
25、s and the specific testingprotocols that include this test method.12.2 A somewhat limited Type 1 (interlaboratory) precisionwith three laboratories on two different days was evaluated in1988. The results are given in Table 1. Both repeatability andreproducibility are short term. A period of a few da
26、ys separatesreplicate test results.Atest result is the mean value, as specifiedby this test method, obtained on two determinations or mea-surements of the property or parameter in question.12.3 The precision of this test method may be expressed inthe format of the following statements which use what
27、 is calledan “appropriate value of r, R,(r), or (R), that is, that value tobe used in decisions about test results (obtained with the 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
28、any givenmaterial, analysis procedure, and test method in routine testingoperations.12.4 RepeatabilityThe repeatability, r, of this test methodhas been established as the appropriate value tabulated inTable 1. Two single test results, obtained under normal testTABLE 1 Type 1 Precision Percent Insolu
29、blesMaterial AverageWithin Laboratory Between LaboratorySrAr (r) SRR (R)CBS 0.43 0.045 0.129 30.1 0.161 0.456 106.0MBS 0.52 0.024 0.068 13.1 0.057 0.163 31.4DCBS 0.82 0.040 0.115 14.0 0.128 0.363 44.1Pooled valuesB0.59 0.038 0.107 18.2 0.123 0.349 59.1ASr= repeatability standard deviation.r = repeat
30、ability = 2.83 times the square root of the repeatability variance.(r) = repeatability (as a percent of material average).SR= reproducibility standard deviation.R = reproducibility = 2.83 times the square root of the reproducibility variance.(R) = reproducibility (as a percent of material average).B
31、No values omitted.D4934 02 (2012)2procedures, that differ by more than this tabulated r (for anygiven level) must be considered as derived from different ornonidentical sample populations.12.5 ReproducibilityThe reproducibility, R, of this testmethod has been established as the appropriate value tab
32、ulatedin Table 1. Two single test results obtained in two differentlaboratories, under normal test procedures, that differ by morethan the tabulated R (for any given level) must be consideredto have come from different or nonidentical sample popula-tions.12.6 Repeatability and reproducibility expres
33、sed as a per-cent of the mean level, (r) and (R), have equivalent applicationstatements as above for r and R. For the (r) and (R) statements,the difference in the two single test results is expressed as apercent of the arithmetic mean of the two test results.13. Keywords13.1 insolubles; mercaptobenz
34、othiazole (MBT); mercapto-benzothiazole disulfide (MBTS); rubber accelerators; rubberchemicals;2-benzothiazole sulfenamidesASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expr
35、essly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revise
36、d, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may
37、attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee 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 State
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