1、Designation: D2663 14Standard Test Methods forCarbon BlackDispersion in Rubber1This standard is issued under the fixed designation D2663; 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 parent
2、heses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the degree of dispersion ofcarbon black in rubber. Four test methods are described asfollows:SectionsTest Method AVisual Inspe
3、ction 311Test Method BAgglomerate Count 1222Test Method CMicroroughness Measurementwith Profilometer 2333Test Method DMicroroughness Measurement with IFM 34421.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard
4、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.2. Referenced Documents2.1 ASTM S
5、tandards:2D3182 Practice for RubberMaterials, Equipment, and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized SheetsD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries2.2 ASTM Adjuncts:Carbon Black Dispersi
6、on Standards3Carbon Black Dispersion Chart4TEST METHOD AVISUAL INSPECTION3. Scope3.1 Test Method A is a qualitative visual test method.Ratings are made against a set of standard photographs (Fig.1),3and the results are expressed on a numerical scale.This testmethod cannot be used for compounds that
7、contain fillers otherthan carbon black.4. Summary of Test Method4.1 The compound rubber is torn or cut to expose a freshsurface for examination by the eye, aided preferably by a handlens or a low-power binocular microscope. The dispersionlevel of the carbon black is compared against a series of five
8、photographic standards and then rated numerically from 1(very low) to 5 (high) (see Fig. 1).5. Significance and Use5.1 Visual dispersion ratings correlate with certain impor-tant physical properties of the compound. A rating of 5indicates a state of dispersion developing near maximumproperties, whil
9、e a rating of 1 would indicate a state ofdispersion developing considerably depressed properties.Normally, the visual dispersion ratings indicate the followinglevels of compound quality:Visual Dispersion Rating Classification4to5 High3 to 4 Intermediate2to3 Low1 to 2 Very low6. Apparatus6.1 Sharp Kn
10、ife or Razor Blade.6.2 Hand Lens (10) or binocular microscope (10 to 20).6.3 Illuminator, microscopical-type.6.4 Knife Heater.6.5 Series of Photographic Standards, rating 1 to 5. Thesestandards give the following percent dispersion ratings by theAgglomerate Count Method:Visual Rating Black Dispersed
11、, %170283914965991These test methods are under the jurisdiction of ASTM Committee D24 onCarbon Black and are the direct responsibility of Subcommittee D24.71 on CarbonBlack Testing in Rubber.Current edition approved Jan. 1, 2014. Published February 2014. Originallyapproved in 1967. Last previous edi
12、tion approved in 2008 as D2663 08. DOI:10.1520/D2663-14.2For 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.3Avai
13、lable from ASTM International Headquarters. Order Adjunct No.ADJD266302. Original adjunct produced in 1967.4Available from ASTM International Headquarters. Order Adjunct No.ADJD266301. Original adjunct produced in 1967.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohock
14、en, PA 19428-2959. United States17. Test Specimen7.1 Vulcanized CompoundsUse a slab of rubber about2 mm in thickness. Tear it so that a fresh surface is exposed.The tear may be initiated by a small cut. The most nearly flatpart of the tear is used for rating.7.2 Unvulcanized CompoundsUnvulcanized ru
15、bber maybe examined as follows:7.2.1 If the specimen contains curing agents, sheet it out andcure in a press to form a vulcanized slab about 2 mm inthickness. Mill and cure in accordance with Practice D3182.Then proceed as in 7.1.7.2.2 If the specimen contains no curatives, add the appro-priate mate
16、rials with a minimum of mixing. Then cure andproceed as above.7.2.3 If the specimen contains no curatives and a dispersionevaluation with no further mixing is required, the compoundmust first be compressed to remove most of the air holes. Toaccomplish this, press the rubber into a slab between thinF
17、IG. 1 Carbon Black Dispersion StandardsVisual Analysis of Torn VulcanizatesD2663 142sheets of plastic in a mold at a pressure of about 1.03 kPa for5 min at 105C. Care should be taken to avoid excessive flowduring this step. The surface to be examined is formed with asmooth cutting stroke using a sha
18、rp, hot knife (a standard typeknife heater may be employed). The most nearly smooth andflat part of the cut surface is used for rating.8. Number of Tests8.1 Preferably more than one test (on different tears) shouldbe made for each specimen. If convenient, more than oneoperator should rate the sample
19、s.9. Procedure9.1 Examine the prepared specimens under a hand lens orbinocular microscope (the latter being preferred), with obliqueillumination to accentuate surface detail. Keep the magnifica-tion and lighting conditions constant for all specimens.9.2 Compare the size and frequency of carbon agglo
20、meratesin the specimens (showing up as surface bumps or depressions)to the photographic standards. Then assign the most closelymatched numerical rating to each compound being rated. Inborderline cases, use fractional ratings, for example, 312 wouldindicate a rating between 3 and 4. In cases of dissi
21、milarity inthe size and frequency of the agglomerates in the specimen andthose of the standards, the operator shall assign the rating thatin his judgment is most applicable. Certain compounds (forexample, NR and IR) are particularly prone to very small blackagglomerations which are difficult to reso
22、lve by the VisualInspection Method. In instances of high agglomeratefrequency, the surface of stocks of this type may show ageneral roughness or fine pebbled appearance. Differences arebest resolved at somewhat higher magnification (for example,20, binocular microscope). If at all possible, examine
23、com-pounds of this type also by the agglomerate count method, atleast until sufficient experience is gained to recognize disper-sion differences with the Visual Inspection Method.9.3 In comparing a series of different compounds, it is alsodesirable to rate the specimens side by side rather than one
24、ata time. This use of a control compound is also advisable. Thisis best prepared by individual operators, since dispersionrequirements may vary greatly for different types of com-pounds. The control sample should represent a minimumacceptable dispersion level for the type of compound beingrated. Bec
25、ause it can be observed side by side with unknownsamples under identical conditions, a control compound ismore accurate than the photographic standards in discerningsmall deviations from what is considered the norm for aspecific type of compound. Prepare a fresh surface on thecontrol as often as nec
26、essary to ensure cleanliness.10. Report10.1 Ratings:10.1.1 List all ratings, including those on any controlcompound, on the basis of the 1 to 5 scale defined by thestandard photographs. Use fractional ratings when necessary.10.1.2 Average the ratings on different specimens of thesame compound as wel
27、l as the ratings of different operators.Report the final average values.10.2 Compound Identification:10.2.1 FormulationWhenever possible list the following:10.2.1.1 Carbon black, type and loading,10.2.1.2 Other fillers, type and loading,10.2.1.3 Polymer type, and10.2.1.4 Extender oil, type and loadi
28、ng.10.2.2 MixingDescribe the mixing of the compound interms of one or more of the following:10.2.2.1 Standard mixing procedure,10.2.2.2 Type of equipment,10.2.2.3 Masterbatch,10.2.2.4 Finished compound (vulcanized), and10.2.2.5 Finished compound (unvulcanized).11. Precision and Bias11.1 No statement
29、 is made about either the precision or thebias of Test Method A since the result is qualitative and notapplicable to statistical treatment.TEST METHOD BAGGLOMERATE COUNT12. Scope12.1 Test Method B is a quantitative test method. Dispersionis evaluated by measuring with a light microscope the percent-
30、age area covered by black agglomerates in microtomed sec-tions of the compound. Since this test method involves directmeasurement, it is quantitative and more accurate than thevisual test method. The test is applicable to the analysis ofcarbon black dispersion in compounds that contain other fillers
31、.13. Summary of Test Method13.1 The compounded rubber is microtomed into sectionssufficiently thin to permit observation of the carbon agglom-erates by transmitted light, with the aid of a light microscope.The total cross-sectional area of all agglomerates 5 m orlarger is counted, and from the known
32、 content of carbon blackin the stock, the percentage of carbon black below the 5-msize is calculated and expressed as “Percentage of CarbonBlack Dispersed.”14. Significance and Use14.1 Certain important physical properties of the compoundare influenced significantly by the degree of carbon blackdisp
33、ersion within the compound (for example, tensile strengthand abrasion resistance). The correlation of these propertieswith the percentage dispersion determined by the AgglomerateCount Method approximates the following pattern for manytypes of black loaded rubber compounds:Dispersion, % Classificatio
34、nAbove 99 Very high97 to 99 High95 to 97 Intermediate92 to 95 LowBelow 92 Very lowD2663 14315. Apparatus15.1 MicrotomeA rotary microtome5capable of produc-ing sections from samples up to 3 mm in cross-section and 1cm in length. Tungsten carbide knives are recommended. (SeeFig. 2.)15.2 Cryogenic Cool
35、ing UnitA cryogenic cooling attach-ment for the above rotary microtome6capable of cooling thesample to 160C. (See Fig. 2.)15.3 MicroscopeAn optical microscope with binocularviewing and digital image capture is recommended. Thisshould include a movable specimen stage and white lightsource with variab
36、le intensity. Lenses should include two 10wide field eyepieces and objectives in the range from 6 to 10.Taking into account microscope tube corrections, objectivesshould be selected so that magnifications in the range from 75to 100 are available. (See Fig. 3.)15.4 ComputerA computer should be availa
37、ble and inter-faced to the digital camera on the microscope to capture digitalphotomicrographs of the specimens. (See Fig. 3.)15.5 Image Analysis SoftwareSuitable image analysissoftware to allow thresholding of the captured micrographs,conversion of the thresholded image to binary and area fractiond
38、etermination from the binary images. Examples of this type ofsoftware include, but are not limited to, Image J, ImagePro,NIH Image, IDL, and NIST Lispix.15.6 Razor Blades.15.7 Sable Brushes (00).15.8 Microscope Slides and Cover Glasses.16. Reagents and Materials16.1 Liquid Nitrogen.5Example, Leica R
39、M2265.6Example, Leica LN22.FIG. 2 Rotary Microtome with Cryogenic Attachment for Sectioning Rubber SpecimensD2663 14416.2 Organic SolventsAppropriate organic liquid to aid inflattening section onto the glass microscope slides. Examplesinclude xylenes, toluene, and methanol.17. Sampling17.1 Vulcaniza
40、tesSpecimens may be cut from standardtest sheets (about 2-mm thick) or from pieces of actual curedarticles. Vulcanized samples must be employed because of thesolvent used to uncurl the thin sections. If pieces other than2-mm sheets are used, they should first be cut down to athickness of about 2 to
41、3 mm.17.2 Unvulcanized CompoundsFor rubbers of high un-saturation (for example, OE-SBR, NR, and BR), dust small bits(enough subsequently to form buttons about 10 mm in diameterand about 2 to 3-mm deep) thoroughly with dicumyl peroxide.Cure in a button mold7under high pressure at about 155C.OE-SBR ru
42、bbers require about 30 to 60-min cure. BR requiresabout 10 to 15-min cure. After cure, scrape off the excessperoxide from the sample surface and proceed with sectioningin the standard manner, taking care not to pare down below thecured surface layer.17.2.1 For IIR, satisfactory surface cures can be
43、obtainedwith a mixture of 1 part tetramethylthiuram disulfide (TMTD),1 part mercaptobenzothiazole (MBT), 1 part sulfur, and 5 partszinc oxide, with a cure of 1 h at 155C. Other alternativeapproaches for curing high unsaturation polymers withoutactually mixing in curatives are (1) high-energy radiati
44、on and(2) chemical treatment with sulfur monochloride. However,before using either of these latter methods, the stock should bepressed out to eliminate most of the air holes. Cure inaccordance with Practice D3182.18. Test Specimen18.1 Cut out a specimen approximately 1 cm long, 1 cmwide, and approxi
45、mately 2-mm deep.18.2 Cut the square block into a trapezoidal shape that willfit the sample chuck on the rotary microtome.18.3 Prepare one specimen block for each different com-pound to be examined.19. Procedure19.1 Microtome PreparationTurn on the rotarymicrotome, insert the knife into the microtom
46、e and adjust tothe correct cutting angle (see microtome manufacturer instruc-tions). Fill the liquid nitrogen dewar and attach to the cryo-genic chamber on the microtome. Cool the microtome chamberand knife holder.19.2 Sample PreparationInsert the prepared specimenblock into the microtome chuck and
47、insert the chuck into themicrotome such that the long axis of the specimen is parallel tothe cutting direction. Cool the sample to approximately 50Cbelow the elastomer glass transition temperature.19.3 Microtome OperationManually advance the speci-men so that the cutting face almost reaches the knif
48、e. At thispoint, with the advance set in increments of 5 to 10 m, startmicrotoming until the specimen is faced level and full-sizesections are being cut.19.4 Cutting Thin SectionsAfter facing is complete, setthe microtome control to the appropriate thickness depending7A special mold containing sever
49、al circular cavities that are approximately10 mm in diameter and 3 mm deep.FIG. 3 Light Microscope Equipped with Digital Camera and Computer SystemD2663 145on the carbon black loading. For standard elastomer com-pounds a thickness of 1 to 2 m is a good starting point. Cut 4to 5 sections, which will likely roll up, and allow the sectionsto collect on the back side of the knife and knife holder.19.5 Mounting Sections on Microscope SlidesUsing aclean, dry sable brush transfer a section from the knife block toa clean microscope slide
