1、Designation: D 3677 00 (Reapproved 2004)Standard Test Methods forRubberIdentification by Infrared Spectrophotometry1This standard is issued under the fixed designation D 3677; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These test methods cover rubber
3、 identification and arebased on infrared examination of pyrolysis products (pyrolyz-ates) and films.1.2 These test methods are applicable to rubbers in the rawstate and, when compounded, both in the cured and uncuredstate.1.3 The values stated in SI units are to be regarded asstandard.1.4 This stand
4、ard 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. Specific precau-tionary stat
5、ements are given in Section 17.2. Referenced Documents2.1 ASTM Standards:2D 297 Test Methods for Rubber ProductsChemicalAnalysisD 1418 Practice for Rubber and Rubber LaticesNomenclatureD 3452 Practice for RubberIdentification by Pyrolysis-Gas ChromatographyE 168 Practices for General Techniques of I
6、nfrared Quanti-tative Analysis3. Significance and Use3.1 For research, development, and quality control pur-poses, it is advantageous to determine the composition ofrubbers in cured, compounded products.3.2 This test method provides such composition analysisutilizing an infrared technique.4. Reagent
7、s4.1 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 Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades ma
8、y beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.4.2 Acetone.4.3 Alcohol, specially denatured (Formula 2-B or 30 issatisfactory).4.4 2-Butanone.4.5 Chloroform.4.6 Congo Red Paper.4.7 Diatoma
9、ceous Filter Aid4,5Some grades are quiteunsatisfactory in that they will not sufficiently absorb carbonblack.4.8 1,2-Dichlorobenzene6, 5Acheck on suitability may bemade by evaporating 50 cm3to dryness and making an infraredspectrum of the residue. Any substantial absorbance at posi-tions near those
10、wavenumbers that will be used for rubberanalysis, indicates that the 1,2-dichlorobenzene is unsuitablefor use.4.9 Dry Compressed Air and Nitrogen, in cylinders, orprovided as a laboratory service.4.10 Sodium Sulfate, anhydrous.4.11 Toluene.1These test methods are under the jurisdiction of ASTM Commi
11、ttee D11 onRubber and are the direct responsibility of Subcommittee D11.11 on ChemicalAnalysis.Current edition approved Dec. 1, 2004. Published December 2004. Originallyapproved in 1978. Last previous edition approved in 2000 as D 3677 00.2For referenced ASTM standards, visit the ASTM website, www.a
12、stm.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.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on
13、 the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.4The sole source of supply of the diat
14、omaceous filter aid known to thecommittee at this time is Fisher Scientific, Catalog No. C211 (Celite).5If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible tech
15、nical committee,1which you may attend.6The sole source of supply of 1,2-dichlorobenzene known to the committee atthis time is J. T. Baker Chemical Co., Phillipsburg, NJ 08865, Catalog No. 9217.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United
16、 States.TEST METHOD A QUALITATIVE ANALYSIS5. Scope5.1 This test method, based on infrared examination ofpyrolysis products (pyrolyzates) and films, will identify therubbers in 6.1 occurring alone or in binary blends in the rangefrom 80 % major component to 20 % minor component.Exceptions to this wil
17、l be found in 6.2.5.2 This test method is applicable to rubbers in the raw stateand, when compounded, both in the cured and uncured state.5.3 This test method implies that sample preparation andinfrared spectrum are prepared and analyzed by experiencedpersonnel and that the equipment used for the pr
18、oduction of thespectra is operated according to the manufacturers directionsfor optimum performance. No details for operation of infraredspectrophotometers are included in these test methods.6. Field of Application6.1 Infrared examinations of pyrolyzates and films willidentify mixtures of two of the
19、 following types of rubbers inthe range from 80 % major component to 20 % minor compo-nent. (See the exceptions in 6.2.)6.1.1 Isoprene Rubbers (see 6.2.1):6.1.1.1 Natural rubber, synthetic polyisoprene, gutta percha,and balata are included.6.1.1.2 Examination of the pyrolyzate will not distinguishbe
20、tween the different forms of polyisoprene.6.1.1.3 Examination of a film will distinguish natural andsynthetic polyisoprene from balata and gutta percha.6.1.2 Styrene-Butadiene Rubbers with Styrene Content ofApproximately 23.5 % Styrene (see 6.2.2):6.1.2.1 For the purpose of this standard, all copoly
21、mers ofstyrene and butadiene and their oil-extended forms are in-cluded.6.1.2.2 Examination of the pyrolyzate will not distinguishbetween emulsion and solution polymerized rubbers.6.1.2.3 Examination of films may give some informationabout the monomer ratio and the polymerization system.6.1.3 Acrylo
22、nitrile-Butadiene Rubber with AcrylonitrileContent of Approximately 33 %:6.1.3.1 Examination of the pyrolyzate will not measure theratio of acrylonitrile to butadiene.6.1.3.2 Examination of a film may give some informationabout the acrylonitrile content.6.1.4 Chloroprene RubberThis test method will
23、not dis-tinguish between the different types of chloroprene rubbers.6.1.5 Butyl Rubber This test method will not distinguishbetween butyl rubber and its halogenated forms.6.1.6 Polybutadiene Rubber (High cis):6.1.6.1 Examination of the pyrolyzate will not distinguishbetween polybutadiene rubbers hav
24、ing different isomer ratios.6.1.6.2 Examination of a film may give some informationabout the monomer ratio.6.1.7 Ethylene-Propylene Rubbers (see 6.2.3)This testmethod will not distinguish between rubbers having differentratios of ethylene to propylene nor between copolymers andterpolymers.6.2 Except
25、ions to the rubbers listed in 6.1 are:6.2.1 A blend of natural or synthetic isoprene (20 %) andchloroprene (80 %), or both, may present difficulties, andidentification of the minor component may be achieved onlywhen its content is equal to or more than 30 % in the blend.6.2.2 A blend of butadiene-st
26、yrene rubber (80 %) and highcis polybutadiene rubber (20 %) may present difficulties, andidentification of the minor component may only be achievedwhen it is equal to or more than 30 % in the blend.6.2.3 Ethylene-propylene rubber in blends with other rub-bers present difficulties when its content is
27、 in the range from 20to 40 %.6.3 In difficult cases, examination of the gaseous products ofpyrolysis by gas chromatography (Practice D 3452) may givefurther information.7. Summary of Test Method7.1 Identification from Pyrolyzates:7.1.1 A small quantity of extracted and dried rubber ispyrolyzed in a
28、stream of nitrogen in a test tube held in a smallelectric, thermo-regulated furnace at 450 to 500C, or alterna-tively, rapidly pyrolyzed in a small test tube held in the hotzone of a gas flame.7.1.2 A test for chlorine is conducted during pyrolysis.7.1.3 A few drops of the pyrolyzate are transferred
29、 to a saltplate and an infrared spectrum recorded over the 2.5 to 15-mwavelength region.7.1.4 The rubber is identified by comparison to standardreference spectra and by reference to a table of diagnosticabsorptions (significant absorption frequencies).7.1.5 Each laboratory employing this standard mu
30、st preparespectra of all rubbers they might be expected to identify. Thesespectra must be prepared in the same manner and using thesame equipment as will be used for unknown samples.7.2 Identification from Films:7.2.1 A small quantity of extracted and dried rubber isdissolved in 1,2-dichlorobenzene,
31、 filtered, and a film cast on asalt plate. This film is used as in 7.1.4.7.2.2 A small quantity of extracted and dried rubber issubjected to mild thermal degradation at 200 6 5C for a shorttime. The degraded sample is dissolved in trichloroethylenethen chloroform, and a film cast on a salt plate. Th
32、is film isused as in 7.1.4.8. Apparatus8.1 Extraction Apparatus:8.1.1 The extraction apparatus used shall be of the generaltype and dimensions shown in Fig. 1.8.2 Test Tubes, small, and other necessary glassware suffi-cient to carry out the test as written.8.3 Pyrolysis Apparatus (Fig. 2)The pyrolys
33、is apparatusconsists of a glass tube (P) having inward projections toprevent the sample from falling to the bottom of the tube anda lateral condenser tube. The tube (P) has a ground-glassstandard taper (S) which carries a small glass adductor tube. AD 3677 00 (2004)2collecting tube (T) is placed und
34、er the condenser tube. Anelectric, thermoregulated furnace (F) accommodates an alumi-num block (H) with holes for one or more tubes (P).8.4 Capillary Pipets.8.5 Oven, capable of maintaining a temperature of 200 65C for use in 10.2.8.6 Water Bath, for use in 10.2.8.7 Salt Plates, polished (sodium chl
35、oride or potassiumbromide), 4 by 25 mm, to serve as windows for the spectro-photometer.7,58.8 High-Resolution Infrared Spectrophotometer, doublebeam, capable of recording a spectrum over the 2.5 to 15-m(4000 to 667 cm1or 400 000 to 66 700 m1) region. (Highresolution8requires that the spectral slit w
36、idth should notexceed 2 cm1over 80 % of the wavenumber range and at noplace should it exceed 5 cm1.) Any spectrophotometer com-plying with these requirements may be used. The equipmentshall be operated by an experienced analyst according to themanufacturers directions for optimum performance.9,59. P
37、reparation of Test Portion9.1 Temperature Controlled Pyrolysis in a Stream of Nitro-gen (Fig. 2; Preferred Method):9.1.1 Prepare the test portion by milling into a thin sheet ona laboratory mill or cutting into cubes about 2 mm wide andwrap approximately 0.5 g in filter paper or nylon cloth. Extract
38、the wrapped test portion in an extraction cup in accordancewith Section 18 of Test Methods D 297, for a minimum of 4 hwith methanol, ethanol, or 2-propanol. A vulcanizate may beextracted with acetone or 2-butanone, in addition to the abovealcohols.Alternatively, the rapid reflux procedure may be use
39、dfor1hinaccordance with Section 25 of Test Methods D 297.9.1.2 Remove the extracted rubber from the apparatus anddry at 100C until free of solvent. One to two hours is usuallyrequired.9.1.3 Introduce a small amount of anhydrous sodium sulfateinto the collecting tube (T) to absorb water produced duri
40、ngpyrolysis.9.1.4 Place a strip of moistened Congo red paper across themouth of the tube, as a test for chlorine (a change from red toblue).9.1.5 If alternative chlorine determining methods are em-ployed, this procedure must be suitably modified.9.1.6 Bring the electrical furnace (F) to 450 to 500C
41、andhold at this temperature. This range is recommended to obtainfast pyrolysis, without excessive degradation and carboniza-tion. Temperatures below this range should be avoided.9.1.7 Pass a slow stream of nitrogen through the pyrolysistube and introduce the tube into a hole of the aluminum block(H)
42、. The nitrogen serves to displace air, prevent oxidation, andfacilitate transfer of the pyrolysis products to the collectingtube (T).9.1.8 Carry on heating to complete distillation, which re-quires approximately 15 min.9.1.9 Transfer a few drops of the pyrolyzate from the tube toa sodium chloride or
43、 potassium bromide plate, using a capillarypipet.7The sole source of supply of the salt plates known to the committee at this timeis Barnes Engineering Co., Stamford, CT 06902, Catalog No. 7000-316.8High resolution is defined in “Specification for Evaluation of Research QualityAnalysis of Infrared S
44、pectra,” Analytical Chemistry, ANCHA, Vol 47, No. 11, p.94A.9The sole source of supply of the spectrophotometer known to the committee atthis time is Perkin-Elmer, Model 283, Perkin-Elmer Corp., Norwalk, CT 96856.FIG. 1 Extraction Apparatus with Glass Condenserand Ground Glass JointF electric, therm
45、oregulated furnaceH aluminum block, bored to hold tubesP glass tube for sample containerS ground-glass taperT collecting tubeFIG. 2 Temperature Controlled Pyrolysis ApparatusD 3677 00 (2004)39.1.10 Place a spacer of suitable thickness in position, closethe cell with a second plate of the same materi
46、al, and mount thecell in the infrared spectrophotometer.9.1.11 Record the spectrum over the wavelength range from2.5 to 15 m.9.1.12 Spectra should be obtained immediately after pyroly-sis to minimize further change in the pyrolysis products.9.2 Gas Flame Pyrolysis (Alternative Test Method):9.2.1 Pre
47、pare the extract, dry2goftest portion (9.1.1 and9.1.2), and place 0.1 to 0.2 g of the test portion in the bottomof a small glass test tube. Place a strip of moistened Congo redpaper across the mouth of the tube. Hold the tube horizontally,and quickly bring the lower end containing the test portion i
48、ntothe hot zone of a gas burner, so that the rubber is rapidlypyrolyzed and charring is kept to a minimum. Note any colorchange in the Congo red paper, from red to blue, indicating thepresence of chlorine.9.2.2 Maintain the heating until the pyrolyzate condenses inthe cool end of the tube, withdraw
49、the test tube from the flame,and cool while holding horizontally.9.2.3 Alternatively, the sample may be placed in a smallglass tube and the end of the tube drawn out to a “retort” shapewith a blast lamp. Pyrolysis is carried out as described in 9.2.1.Care should be taken to keep the delivery end of the pyrolysistube warm enough so that pyrolysis products do not condenseand block the opening, causing the tube to explode. Thecondensate can be collected in a small test tube containinganhydrous sodium sulfate to remove moisture. Proceed inaccordance with 9.1.9-
