1、Designation: D4937 96 (Reapproved 2017)Standard Test Method forp-Phenylenediamine Antidegradants Purity by GasChromatography1This standard is issued under the fixed designation D4937; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 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 purityof Class I, II, and III p-phenylenediamine (PPD) a
3、ntidegradantsas described in Classification D4676 by gas chromatography(GC) detection and area normalization for data reduction.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 a
4、ll 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.1.4 This international standard was developed in accor-dance w
5、ith internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standar
6、ds:2D3853 Terminology Relating to Rubber and RubberLaticesAbbreviations for Chemicals Used in Com-poundingD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesD4676 Classification for Rubber Compounding MaterialsAntidegradantsE260 Pra
7、ctice for Packed Column Gas Chromatography2.2 ISO Standard:3ISO 6472 Rubber Compounding IngredientsAbbreviations3. Terminology3.1 Definitions:3.1.1 area normalization, na method of calculating thepercent composition by measuring the area of each observedpeak and dividing each peak area by the total
8、area. Thisassumes that all peaks are eluted and that each component hasthe same detector response.3.1.2 lot sample, na production sample representative of astandard production unit, normally referred to as the sample.3.1.3 specimen, nthe actual material used in the analysis.It must be representative
9、 of the lot sample.3.2 AbbreviationsThe following abbreviations are in ac-cordance with Terminology D3853 and ISO 6472:3.2.1 77PDN,Nbis-(1,4-dimethylpentyl)-p-phenylenedi-amine.3.2.2 DTPDN,N-ditolyl-p-phenylenediamine.3.2.3 IPPDN-isopropyl-N-phenyl-p-phenylenediamine.3.2.4 PPDp-phenylenediamine.3.2.
10、5 6PPDN-(1,3 dimethylbutyl)-N-phenyl-p-phenylenediamine.4. Summary of Test Method4.1 The analysis is performed by temperature programmedGC utilizing either a packed column (Procedure A) or acapillary column (Procedure B). Quantification is achieved byarea normalization using a peak integrator or lab
11、oratory datasystem.5. Significance and Use5.1 This test method is designed to assess the relative purityof production PPDs. These additives are primarily used asantiozonants for tires and other rubber or polymeric products.5.2 Since the results of this test method are based on areanormalization, it
12、assumes that all components are eluted from1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand Rubber-like Materials and is the direct responsibility of Subcommittee D11.11on Chemical Analysis.Current edition approved May 1, 2017. Published June 2017. Originallyapproved in
13、 1989. Last previous edition approved in 2012 as D4937 96 (2012).DOI: 10.1520/D4937-96R17.2For 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 Sum
14、mary page onthe ASTM website.3Available from the American National Standards Institute, 25 W. 43rd St., 4thFloor, New York, NY 10036.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordanc
15、e with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1the column and each component has th
16、e same detector re-sponse. Although this is not strictly true, the errors introducedare relatively small and much the same for all samples; thus,they can be ignored since the intent of the test method is toestablish relative purity.5.3 Although trace amounts of “low boilers” are present inproduction
17、 samples, they are disguised by the solvent peakwhen using packed columns (Procedure A).6. Interferences6.1 Utilizing the chromatographic conditions prescribedthere are no significant co-eluting peaks; however, degradationof column performance could result in interference problems.Thus, when using t
18、he packed column it is essential that thetotal system be capable of 5000 theoretical plates before beingused for this analysis. The evaluation of system efficiency isdescribed in 7.4.7. Apparatus7.1 Gas Chromatograph:7.1.1 Procedure A: Packed ColumnAny high-quality tem-perature programmed gas chroma
19、tograph equipped with athermal conductivity detector (see Note 1) is sufficient for thisanalysis. Refer to Practice E260 for general gas chromatogra-phy practices.NOTE 1Although a thermal conductivity detector is recommended, aflame ionization detector can be used if appropriate adjustment is made f
20、orflow rate and specimen size. Since this probably would involve using asmaller diameter column, the adjustment in flow and injection volumeshould be proportional to the cross-sectional area of the column. Aprocedure for this calculation is included at the end of Section 9.7.1.2 Procedure B: Capilla
21、ry ColumnA temperature pro-grammable unit with flame ionization detector (FID) equippedfor capillary columns. When utilizing the full capillary col-umns (0.25 mm), a split injection system is required; howevera “cold on-column” injector is preferred for the wide bore(0.53 mm) capillaries. The FID sh
22、ould have sufficient sensitiv-ity to give a minimum peak height response of 30 V for 0.1mass % of 6PPD when operated at the stated conditions.Background noise at these conditions is not to exceed 3 V.7.2 Gas Chromatographic Columns:7.2.1 Packed Column for Procedure A1.828 m 6.35 mm(6 ft 14 in.) outs
23、ide diameter 4 mm (0.16 in.) insidediameter glass columns packed with 10 % methyl silicone fluid(100 %) on 80/100 mesh acid washed and silanized diatomitesupport. The column should be conditioned with a helium flowof approximately 20 cm3/min by programming from ambienttemperature to 350C at the rate
24、 of 2 to 3C/min and holdingat 350C overnight with the detector disconnected.7.2.2 Capillary Column for Procedure B(1) 30 m 0.25mm ID fused silica capillary, internally coated to a filmthickness of 0.25 m (bonded) with methyl silicone; (2)15m 0.53 mm fused silica (megabore) capillary with 3.0 mbonded
25、 film of 5 % phenyl silicone, HP-5 or equivalent.7.3 Integrator/Data System, capable of determining therelative amount of each component by means of integration ofthe detector output versus time. When using capillary columns(Procedure B) the device must integrate at a sufficiently fastrate so that n
26、arrow peaks (one second peak width) can beaccurately measured.7.4 When using a packed column, a minimum of 5000theoretical plates, as measured from the 6PPD peak, with thechromatographic conditions stated in 9.1 is required for analy-sis. Theoretical plates (TP) are determined by the followingformul
27、a:TP 5 5.5 XR!/Y0/5!#2(1)where:X(R) = retention time measured from the injection point tothe apex of the 6PPD peak (adjust the attenuationto keep peak on scale), mm, andY(0.5) = 6PPD band width at half-height, mm.8. Calibration and Standardization8.1 When using the conditions described for Procedure
28、 A(packed column), the detector response of 6PPD for injectionsof 500 to 5000 g was found to be somewhat nonlinear (seeX1.3). However, over the more limited range, 750 to 2500 g,the response was nearly linear (see X1.4). As a result, it issuggested that the samples be prepared so that 1250 to 1500 g
29、injections are made.8.2 Chromatograms from typical specimens run on thepacked columns according to the prescribed procedure aregiven in Appendix X1.9. Procedure9.1 Procedure AChromatographic Conditions:Helium flow rate 50 cm3/minInjection port temperature 300CInitial column temperature 100CHeating r
30、ate 8C/minFinal Temperature 350CDetector temperature 350CDetector: TC attenuation 89.1.1 Integrator/data system parameters are presented inX1.2.9.1.2 Specimen PreparationTo ensure specimenhomogeneity, lot samples of 6PPD should be ground with amortar and pestle prior to weighing the test unit. In th
31、e case ofliquid 6PPD where partial crystallization may have occurredresulting in fractionation, the lot sample should be melted in a50 to 60C oven with occasional stirring, prior to weighing thetest unit.9.2 Procedure AAnalysis:9.2.1 Weigh 2.5 to 3.0 g specimen (to the nearest milligram)intoa10cm3vo
32、lumetric flask, dilute to volume with methyl-ene chloride, and shake well to dissolve.9.2.2 When the instrument has equilibrated at the initialconditions described in 9.1, inject 5.0 mm3(L) of samplesolution and initiate the temperature program and data collec-tion.9.2.3 When the run is complete, in
33、spect the chromatogramand output data for proper appearance and peak identification(see X1.1).9.2.4 Repeat the run described in 9.2.2 on the same speci-men.D4937 96 (2017)2NOTE 2Specimen size and carrier gas flow rates should be adjusted inaccordance with the cross-sectional area of the column utili
34、zed. Forexample, if a nominal18 in. outside diameter column (1.87 mm insidediameter) is used rather than a14 in. outside column (3.54 mm insidediameter), the adjustment would be as follows: The ratio of cross-sectionalareas is 3.54/1.87 squared, which equals 3.6. Thus, the sample size andhelium carr
35、ier flow rate should be decreased by this factor; that is, the flowrate of 50/3.6 or 14 cm3/min and sample size to 5/3.6 or 1.4 mm3(L).9.3 Procedure B: Chromatographic ConditionsThe sug-gested operating conditions for the analysis using a capillarycolumn are given in Table 1. Column (1) is for a sta
36、ndardcapillary and Column (2) is for a megabore capillary.9.4 Procedure BSample Analysis:9.4.1 Prepare the sample as in 9.1.2 and the test specimenaccording to Table 1.9.4.2 When the instrument has equilibrated at the initialconditions described in Table 1, inject the indicated amount ofdiluted test
37、 specimen and immediately start the recorder,integrator, and column temperature programming sequence.9.4.3 When the run is complete, inspect the chromatogramand output data for proper appearance and peak identification.Typical chromatograms on the 0.53 mm megabore capillary isshown in Figs. X2.1-X2.
38、4 (6PPD) respectively.9.4.4 Repeat the run described in 9.4.2 on the same speci-men.10. Calculation10.1 Calculate the relative area percent of 6PPD and theother identified components as follows:A 5AC/AT!3100% (2)where:A = area of 6PPD, %,AC= area of component, andAT= total area.11. Report11.1 Report
39、 the following information:11.1.1 The combined area of all unidentified peaks aspercent other,11.1.2 All results to the nearest 0.1 %, and11.2 The final report should include proper identification ofthe specimen and the data from the two individual injectionsplus their average.12. Precision and Bias
40、Procedure A12.1 This precision and bias section has been prepared inaccordance with Practice D4483. Refer to Practice D4483 forterminology and other statistical details.12.1.1 The precision results in this precision and biassection give an estimate of the precision of this test methodwith the materi
41、als (antidegradants) used in the particularinterlaboratory programs as described below. The precisionparameters should not be used for acceptance/rejection testingof any group of materials without documentation that they areapplicable to those particular materials and the specific testingprotocols t
42、hat include this test method.12.2 A Type 1 (interlaboratory) precision was evaluated in1987. Both repeatability and reproducibility are short term. Aperiod of a few days separates replicate test results.Atest resultis the mean value, as specified by this test method, obtained ontwo determinations or
43、 measurements of the property or param-eter in question.12.3 Four different materials were used in the interlabora-tory program. These were tested in four laboratories on twodifferent days.12.4 The results of the precision calculations for repeatabil-ity and reproducibility are given in Table 2, in
44、ascending orderof material average or level, for each of the materials evalu-ated.12.5 The precision of this test method may be expressed inthe format of the following statements which use an “appro-priate value” or r, R,(r), or (R), that is, that value to be used indecisions about test results (obt
45、ained with the test method).The appropriate value is that value of r or R associated with amean level in Table 2 closest to the mean level underconsideration at any given time, for any given material, inroutine testing operations.12.6 RepeatabilityThe repeatability, r, of this test methodhas been es
46、tablished as the appropriate value tabulated in Table1. Two single test results, obtained under normal test methodprocedures, that differ by more than this tabulated r (for anygiven level) must be considered as derived from different ornonidentical sample populations.12.7 ReproducibilityThe reproduc
47、ibility, R, of this testmethod has been established as the appropriate value tabulatedin Table 2. Two single test results obtained in two differentlaboratories, under normal test method procedures, that differby more than the tabulated R (for any given level) must beconsidered to have come from diff
48、erent or nonidentical samplepopulations.TABLE 1 Procedure BChromatographic ConditionsColumn (1) 30 m 0.25 mm (2) 15 m 0.53 mmStationary Phase bonded methyl silicone bonded 5 % phenylsiliconeFilm thickness 0.25 m 3.0 mCarrier gas (helium) (helium)Linear velocity at 100C 0.34 m/sec NAFlow rate 1.0 cm3
49、/min 30.0 cm3/minHead pressure 60 kPa, gauge (9 psig) NADetector FID FIDDetector Temperature 300C 300CInjection Port Temperature 300C oven trackingHydrogen Flow RateA30 cm3/min 30 cm3/minAir Flow RateA300 cm3/min 300 cm3/minMakeup Gas Nitrogen or Helium Nitrogen or HeliumMakeup Flow RateA29 cm3/min 10 cm3/minSplit Ratio 180:1 (no split)Column TemperatureProgramRamp A Ramp BInitial temperature 42C 35C 240CProgram rate 9C/min 15C/min 8C/minFinal temperature 300C 240C 290CTime at finaltemperature22 m
