1、Designation: D297 13Standard Test Methods forRubber ProductsChemical Analysis1This standard is issued under the fixed designation D297; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenthe
2、ses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These test methods cover the qualitative and quantita-tive analysis of t
3、he composition of rubber products of the “R”family (see 3.1). Many of these test methods may be applied tothe analysis of natural and synthetic crude rubbers.1.1.1 Part A consists of general test methods for use in thedetermination of some or all of the major constituents of arubber product.1.1.2 Pa
4、rt B covers the determination of specific polymerspresent in a rubber product.1.1.3 The test methods appear in the following order:Part A. General Test Methods: SectionsRubber Polymer Content by the Indirect Method 11-13Determinations and Report for the General Method 14 and 15Density 16Extract Anal
5、ysis 17-26Sulfur Analysis 27-33Fillers Analysis 34-40Ash Analysis 41-51Part B. Determination of Rubber Polymers 52-581.2 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety
6、 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. Specific precau-tionary or warning statements are given in 31.4.5, 31.6, 37.
7、4.2,38.4.2, 45.1.3, 53.2.3.5, 54.4.2, 54.6, 56.5.3, and 57.7.3; andX1.3.3 and X2.4.1.6.2. Referenced Documents2.1 ASTM Standards:2D982 Test Method for Organic Nitrogen in Paper andPaperboardD1416 Test Methods for Rubber from Synthetic SourcesChemical Analysis (Withdrawn 1996)3D1418 Practice for Rubb
8、er and Rubber LaticesNomenclatureD1646 Test Methods for RubberViscosity, StressRelaxation, and Pre-Vulcanization Characteristics(Mooney Viscometer)D3040 Practice for Preparing Precision Statements for Stan-dards Related to Rubber and Rubber Testing (Withdrawn1987)3D3156 Practice for RubberChromatogr
9、aphic Analysis ofAntidegradants (Antioxidants, Antiozonants and Stabiliz-ers)D3452 Practice for RubberIdentification by Pyrolysis-GasChromatographyD3677 Test Methods for RubberIdentification by InfraredSpectrophotometryD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber an
10、d Carbon Black ManufacturingIndustriesE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE131 Terminology Relating to Molecular SpectroscopyE200 Practice for Preparation, Standardization, and Storageof Standard and Reagent Solutions for Chemical AnalysisE442 Test Method for Chlorine, Br
11、omine, or Iodine inOrganic Compounds by Oxygen Flask Combustion (With-drawn 1996)3E443 Test Method for Sulfur in Organic Compounds byOxygen Flask Combustion (Withdrawn 1996)33. Terminology3.1 DefinitionsThe nomenclature and abbreviations usedfor natural and synthetic rubbers are in accordance withPr
12、actice D1418.1These test methods are under the jurisdiction of ASTM Committee D11 onRubber and are the direct responsibility of Subcommittee D11.11 on ChemicalAnalysis.Current edition approved May 1, 2013. Published May 2013. Originallyapproved in 1928. Last previous edition approved in 2006 as D297
13、 93 (2006).DOI: 10.1520/D0297-13.2For 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 Summary page onthe ASTM website.3The last approved version o
14、f this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Reagents4.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended tha
15、tall reagents shall conform to the specifications of the 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 less
16、ening theaccuracy of the determination.4.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean distilled water or water ofequal purity.5. Concentration of Reagents5.1 Concentrated Acids and Ammonium HydroxideWhenacids and ammonium hydroxide are specified by name
17、 orchemical formula only, it is understood that concentratedreagents of the following densities or concentrations areintended:Density,Mg/m3Acetic acid, HC2H3O2(99.7 %) 1.05Formic acid, HCOOH 1.22Hydrochloric acid, HCl 1.19Hydrofluoric acid, HF (49 %) 1.16Nitric acid, HNO31.42Phosphoric acid, H3PO4(8
18、5 %) 1.70Sulfuric acid, H2SO41.84Ammonium hydroxide, NH4OH 0.90The desired densities or concentrations of all other concen-trated acids are stated whenever they are specified.5.2 Diluted Acids and Ammonium HydroxideConcentrations of diluted acids and ammonium hydroxide,except when standardized, are
19、specified as a ratio stating thenumber of volumes of the concentrated reagent to be added toa given number of volumes of water, as in the followingexample: HCl (1 + 9) means 1 volume of concentrated HCl(density 1.19) mixed with 9 volumes of water. Acids shall beadded to water slowly, with stirring.5
20、.3 Standard SolutionsConcentrations of standard solu-tions are expressed as normalities or as volume of solution thatreacts with or contains a given mass of material being used ordetermined, for example: 0.1 N Na2S2O3solution, or CuSO4solution (1 cm3= 0.001 g Cu).5.4 Nonstandardized SolutionsConcent
21、rations of nonstan-dardized solutions prepared by dissolving a given mass in asolvent are specified in grams of the reagent (as weightedout)/dm3of solution, and it is understood that water is thesolvent unless otherwise specified, for example: NaOH (10g/dm3) means 10 g of NaOH dissolved in water and
22、 dilutedwith water to 1 dm3(Note 1). In the case of certain reagents theconcentration may be specified as a percentage by mass, forexample: ethanol (50 %) means a solution containing 50 g ofethanol per 100 g of solution. Other nonstandardized solutionsmay be specified by name only, and the concentra
23、tion of suchsolutions will be governed by the instructions for their prepa-ration.NOTE 1Whenever a hydrated salt is used in the preparation of areagent (for example, BaCl22H2O) the preparation of the reagent isdescribed in detail. When an anhydrous salt is used in preparing a simpleaqueous solution
24、the reagent is listed by title only and details of thepreparation are not given.PART A. GENERAL TEST METHODS6. Scope and Application6.1 The general test methods described cover the analysis ofmany types of rubber products to determine the amount andtype of nonrubber constituents and to calculate ind
25、irectly fromthese data the amount of rubber constituent.6.2 The applications and limitations of the test methods toanalysis of specific types of rubber products are given in thescopes of the various test methods. Application to types ofrubber products not specified in the scope of a particular testm
26、ethod shall be verified by application to a control of knownand similar composition.6.3 Special test methods for analysis are given for rubberproducts containing glue, free carbon, antimony, lead, mineraloil, waxy hydrocarbons, and barium carbonate.6.4 For the determination of the amount of a rubber
27、 polymerpresent in a rubber product, an indirect test method is given bywhich the nonrubber constituents are determined individuallyor in groups, and the rubber polymer content is determined bydifference (Sections 11-13). If, in using this test method, fillersare determined by the ashing test method
28、 (Section 35 or 36),satisfactory results will be obtained, except where there arefound to be present decomposable compounding ingredientssuch as carbonates that decompose at 550C, clay, asbestine,talc, hydrated silica, antimony sulfide, halogen-containingcomponents, and silicone polymers. No test me
29、thod of fillerdetermination herein described will give accurate results in thepresence of clay, silica, talc, or any other hydrated filler unlessa correction can be made for losses of water of hydration onashing. This correction can be made only if the nature andquantity of these fillers are known.
30、The indirect test methodwill not give accurate results in the presence of halogen-containing components or silicone rubber. In the presence ofantimony sulfide or carbonates decomposing at 550C, but inthe absence of the above interfering constituents, approximatecorrection can be made by means of det
31、ermination of totalantimony (Section 50) or of the metal associated with the4Reagent 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 Laborat
32、oryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.D297 132decomposable carbonate (usually calcium, Section 45)or(Section 49) and calculation of the original composition of thecompounding in
33、gredient from these data.6.5 If factice or high percentages of mineral rubber arepresent, no accurate test method is known for determination ofrubber content or for complete analysis of the rubber product.6.6 For the determination of the rubber content of hardrubber products, no accurate test method
34、 is described herein iffillers decomposable at 550C are present.7. Blank Determinations7.1 Blanks shall be run on all determinations to check thepurity of the materials used and deductions shall be madeaccordingly.8. Check Analyses8.1 Duplicate determinations shall be made and shall checkwithin the
35、limits specified in the test method, when these arestated.9. Preparation of Samples9.1 Before preparing a sample for analysis, the analyst shall,by inspection, assure himself that it has not been contaminated.The sample to be analyzed shall be selected by taking piecesfrom various parts of the origi
36、nal sample and separating themfrom foreign matter. Because of the variety of rubber productsto which this test method can be applied, no single procedurefor reducing the sample to the required fineness is applicable toall samples. Therefore, several alternative procedures for thispurpose are describ
37、ed in 9.2 to 9.7. The analyst is expected toselect the one most suitable to the sample that he is analyzingand the equipment available.9.2 For vulcanized soft rubber, unvulcanized rubber, cruderubber, and many samples of reclaimed rubber, it is preferableto mix the sample and grind it by passing it
38、two or three timesthrough a clean, cold, laboratory rubber mill. The rubber willcome from the mill in the form of a coarse powder or a roughsheet. If the product is in the form of a sheet, the adjustment ofthe mill shall be such that the thickness of the final sheet is nogreater than 0.5 mm. If the
39、sample is sticky, it shall be rolledin a liner material that will not adhere to or contaminate thesample. If the milled sample is a powder, it shall be transferredto a No. 14 (1.40-mm) sieve5and rubbed through the sieve.Grinding shall be continued until the entire sample passesthrough the sieve.9.3
40、In the absence of milling machinery, the sample may beprepared by cutting it with scissors so that it will pass a No. 14(1.40-mm) sieve.6,7The sample may be cut into long strips thatare fine enough to pass freely through the sieve and the stripsfed through by hand, or the sample may be cut into smal
41、lfragments and shaken through the sieve. The cutting shall becontinued until the entire sample passes through the sieve. Ifnecessary, to prevent sticking, different fragments of the sievedsample may be segregated by wrapping in a liner material thatwill not adhere to or contaminate the sample.9.4 Ce
42、rtain very glutinous samples may be prepared forextraction analysis as follows: Place a weighed 2-g sample ofthe material between two pieces of ashless filter paper that hasbeen extracted in accordance with Section 21. The papersshould be approximately 500 by 100 mm (20 by 4 in.) and thesample shoul
43、d be placed near one end. Flatten the sample andspread it throughout the length of the filter paper by passing the“sandwich” lengthwise, through a cold, closely set, even-speedrubber calender. The gross thickness of the resulting sheetshould not be greater than 1.0 mm. If a rubber calender is notava
44、ilable, a similar sheet may be obtained by placing thesample in a hydraulic press or a vise. In the latter case, thesample may be roughly spread by hand throughout the lengthof the filter paper and pressure applied to small areas at a timeuntil the whole sample has been flattened.9.5 Samples of rubb
45、erized cloth, whose overall thickness isno greater than 1.0 mm, may be prepared for analysis bycutting them into pieces 1.5 mm square and then mixing well.If the fabric is easily removed, it should be separated, unless ananalysis of the whole cloth is desired.9.6 Samples of rubber cements shall be e
46、vaporated todryness in a vacuum oven at a temperature not higher than30C. The residue may then be analyzed as an unvulcanizedsample. A separate sample of the cement shall be distilledunder reduced pressure if examination of the solvent is desired.9.7 Samples of hard rubber shall be reduced to powder
47、 formby filing, cleaned with a magnet, and sieved through a No. 30(600-m) sieve.6Residue retained on this sieve shall bereduced until the entire sample passes through the sieve.10. Preliminary Examination of Samples10.1 The procedures given in 10.1.1-10.1.9 are for use indetermining the number and k
48、ind of tests that should beconducted to obtain the desired information concerning therubber product.10.1.1 CarbonatesDrop a small piece of sample into a testtube containing HCl saturated with bromine. If a stream ofbubbles is given off, carbonates are present. The test is notapplicable to IIR produc
49、ts.10.1.2 Antimony and LeadAsh a 0.2 to 0.3-g specimen inaccordance with 35.4 or 36.4. Dissolve the ash in 10 cm3ofHCl by heating. Dilute to about 40 cm3and decant or filter thesolution from the residue. Pass H2S into the solution. If ared-orange precipitate forms, antimony is present and may bedetermined on a rubber specimen in accordance with Section50. Organic sulfur shall be determined in accordance with 27.3.Dilute with water to about 400 cm3and again pass in H2S. Ifa black precipitate appears, lead is present and organic andinorganic sulfur shall be dete
