1、Designation: D5596 03 (Reapproved 2016)Standard Test Method ForMicroscopic Evaluation of the Dispersion of Carbon Blackin Polyolefin Geosynthetics1This standard is issued under the fixed designation D5596; the number immediately following the designation indicates the year oforiginal adoption or, in
2、 the 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 equipment, specimen prepara-tion techniques, and procedures
3、 for evaluating the dispersion ofcarbon black in polyolefin geosynthetics containing less than5 % carbon black by weight.1.2 This test method allows for a qualitative evaluation ofcarbon black agglomerates and other inclusions in polyolefingeosynthetics. This evaluation is based on carbon black dis-
4、persion size calculated area within microscopic fields of view.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is
5、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.NOTE 1This test method is for the evaluation of carbon blackdispersion. This test method does not support or evaluate the distr
6、ibutionof carbon black.2. Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD3053 Terminology Relating to Carbon BlackD4439 Terminology for GeosyntheticsE7 Terminology Relating to Metallography3. Terminology3.1 Definitions:3.1.1 carbon black, na material consisting essenti
7、ally ofelemental carbon black in the form of near spherical colloidalparticles and coalesced particle aggregates of colloidal size,obtained by partial combustion or thermal decomposition ofhydrocarbons. (D3053)3.1.2 carbon black agglomerate, na cluster of physicallybound and entangled aggregates. (D
8、3053)3.1.3 geosynthetic, na planar product manufactured frompolymeric material used with soil, rock, earth, or other geo-technical engineering-related material as an integral part of aman-made project, structure, or system. (D4439)3.1.4 micrograph, na graphic reproduction of an object asseen through
9、 the microscope or equivalent optical instrument,at magnifications greater than ten diameters (micrograph). (E7)3.1.5 microtome, n (that is, sliding microtome) an appa-ratus capable of cutting thin slices (less than 20 m inthickness) of various geosynthetic samples.3.1.6 polyolefin, na polymer prepa
10、red by the polymeriza-tion of an olefin(s) as the sole monomer(s). (D883)3.1.7 dispersion, na polyolefin product formulated withcarbon black.3.1.8 distribution, na property of a carbon black formu-lated polyolefin product that refers to the existence of streaks,light or dark, within a microsectioned
11、 sample.4. Summary of Test Method4.1 This test method consists of two parts: (1) microtomespecimen preparation and (2) microscopic evaluation.4.1.1 Microtome Specimen Preparation A sample isclamped in the sample holder, which can be raised or loweredprecisely in increments of approximately 1 m.Arigi
12、d knife isslid manually across the sample so that the specimens range inthickness from 8 to 20 m.4.1.2 Microtome specimen examination: These thin sectionsare evaluated microscopically calculating the largest agglom-erate or inclusion in each random field of view (Rf). Theassociated carbon dispersion
13、 chart can be used to assist todetermining shape and area5. Significance and Use5.1 Carbon black is added to many polymers to providelong-term resistance to ultraviolet-induced degradation. Toachieve this, carbon black should be dispersed uniformly1This test method is under the jurisdiction of ASTM
14、Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.02 on Endur-ance Properties.Current edition approved June 1, 2016. Published June 2016. Originallyapproved in 1994. Last previous edition approved in 2009 as D5596 03(2009).DOI: 10.1520/D5596-03R16.2For referenced AST
15、M 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohoc
16、ken, PA 19428-2959. United States1throughout the as-manufactured geosynthetic material. Thistest method is used to evaluate the uniformity of carbon blackdispersion.5.2 This test method is suitable only for those geosyntheticsthat can be sampled using a rotary or sledge microtome. Thegeometry, stiff
17、ness (hardness), or elasticity of some geosyn-thetic products precludes their being sampled with a micro-tome. The cross-sectional area of the geosynthetic must becomposed of a continuous solid polyolefin material to besampled using a microtome.5.3 Extruded and oriented geogrids will require that mi
18、cro-tome specimens be cut from the nonoriented bars of uniaxialproducts and the non-oriented nodes of biaxial products.6. Equipment6.1 MicrotomeA rotary or sledge-type microtomeequipped with a sample clamp and knife holder is required.Steel knives are recommended; however, glass knives may besuitabl
19、e.6.2 Microtome AccessoriesLubricant, dust cover, andtweezers are recommended.6.3 MicroscopeAn optical microscope with binocularviewing (trinocular type, if micrographs are to be taken) isrecommended. This should include a movable specimen stage.Lenses should include two 10 wide field eyepieces ando
20、bjectives in the range of 5 to 20. Taking into accountmicroscope tube corrections, objectives should be selected sothat final magnifications in the range of 50 to 200 areavailable.6.4 Microscope AccessoriesA calibrated reticle (eyepiecemicrometer) positioned in one of the eyepieces between theeyepie
21、ce-lens and the objective is required.6.5 Light SourceAn external white light source withvariable intensity is required.6.6 Microscope slides and cover slides, required.6.7 Balsam cement or suitable, clear substitute (forexample, clear nail polish), required (Note 2).NOTE 2This clear, adhesive mediu
22、m should not dissolve orchemically interact otherwise with the thin section.6.8 Make a microscope cover slide to obtain random field(Rf) of view. From center point of slide make a mark 5 mm toeither side. Use a straight edge and a glass etcher draw twoparallel lines the length of the slide at the ma
23、rks. Measure 3.2mm from each of the lines toward the outer portion of the slideand make a mark. Etch parallel lines to the original lines.Finished cover should look as Fig. 1.NOTE 3Other techniques can to used to make random field of viewslide as long as the two (2) 3.2 mm opening are positioned for
24、 the randomfield of view.6.9 The Microscope cover slide should be the same size asthe slides that the specimens are placed on. The parallel linesshould allow viewing of all specimens when placed.7. Procedure7.1 SamplingFive samples are selected randomly acrossthe full roll width (where applicable) f
25、or each geosyntheticmaterial to be tested. Geomembrane samples should each beapproximately 2.54 cm (1 in.). Geonet samples are selectedrandomly from five strands across the full roll width. Geogridsamples are selected randomly from five nodes across the fullroll width. Pipe and polyolefin components
26、 of geocompositesamples are also selected at random.7.2 Specimen PreparationUsing a microtome, prepareone microsection in the cross-machine direction from eachgeomembrane specimen (See Note 2). Non-oriented geosyn-thetics material specimens can be prepared without regard toprocessing direction. The
27、use of tetrafluoroethane stiffen spraywill assist microtoming of most materials preventing smearingof carbon black or other constituents in sample. The tetrafluo-roethane spray is used to stiffen the sample to 15 C beforemicrotoming the specimens.FIG. 1 Microscope Cover Slide Overlay ConfigurationD5
28、596 03 (2016)2NOTE 4Some extremely flexible or elastomeric materials (e.g., veryflexible polyethylene) may require micro-sectioning under low tempera-ture conditions. In these instances, the sample to be micro-sectioned andthe microtome knife and sample clamp can be loosely packed in crusheddry ice
29、for approximately 15 minutes or until the specimen, knife, andclamp reach approximately 30 C. The microtome apparatus should beset up so that the specimen can be clamped in place and thin sectionedwithin 1 to 5 minutes of removal from the dry ice. The sample can bestiffened by spraying with tetraflu
30、oroethane before micro-sectioning.Other means of freezing sample is acceptable if no damage to the plasticoccurs.7.3 Each thin section should be (1) thin enough (8 to 20-mthick) to allow for adequate light transmission so that carbonagglomerates can be examined easily during microscopy and(2) free f
31、rom major defects such as gouges caused by a nickedor dull knife, or such as torn or distorted portions of the thinsections caused by over-stressing or rough handling (see Note5). Mount each excised thin section between a microscopeslide and a cover slide, using a suitable clear adhesive medium.NOTE
32、 5Because thin sections 20 m thick are usually too thick topermit adequate light transmission through the thin section, thin sectionsshould be 10 to 15 m thick. These thin sections tend to curl up, makingthem difficult to handle. The use of a light honing oil on the knife helpsthe specimen to stick
33、to the blade, make it easier to slide off the blade andonto the slide glass.7.3.1 Mount five specimens to each slide. Place the micro-scope cover slide over the five specimens. The cover slideshould be placed so that there is a viewing area of eachspecimen. The part of the specimens that is exposed
34、by the twoparallel 3.2 mm viewing area of cover slide is considered therandom field of view (Rf). (See Fig. 1)7.4 Microscope SetupPrepare the microscope for trans-mitted light microscopy with the calibrated reticle positionedbetween one eyepiece lens and the objective.7.5 Place the microscope cover
35、slide (as shown in Fig. 1)ontop of the mounted thin-sections.7.6 Random Field of View (Rf) SelectionBefore attempt-ing any close, microscopic examination of the thin section,place the mounted thin section on the microscope stagepositioned between the light source and the objective. Place themicrosco
36、pe cover slide on top of the mounted thin section sothat each of the field of view overlaps the thin section fully.Thearea of the thin section lying within each of the parallel portionof the microscope cover slide is called a random field of viewor (Rf).7.7 Microscopic EvaluationExamine each (Rf)mic
37、roscopically, and locate the largest carbon agglomerate orinclusion. If the microscope is not at 100, select the objectivethat allows for viewing at 100. Calculate the area of theagglomerate or inclusion. Non-spherical agglomerates calcula-tion is made by diametric area of best fit.7.8 IterationRepe
38、at the procedures given in 7.5 and 7.6until ten readings are recorded. No more than two (Rf)s aretaken from each of no less than five thin sections (Note 6).NOTE 6If specimens from some geosynthetic products are not longenough to provide two full random fields of view (Rf) with the glassoverlay in p
39、osition, additional specimens must be prepared to meet theten-reading requirement.7.9 Record all ten readings (calculation) obtained and ex-press the result rounded to the nearest whole number.8. Reporting8.1 Identify the sample(s) for the material or product tested,including sample type, origin, an
40、d manufacturers code orbatch number.8.2 Method of preparation of the specimens (i.e. microtome,frozen specimen, heated specimen, etc).8.3 Report all 10 (Rf) calculations obtained to the nearestwhole number9. Precision and Bias9.1 PrecisionThe precision of this test method is beingestablished.9.2 Bia
41、sNo justifiable statement can be made on the biasof this test method since the true value cannot be established byaccepted referee methods.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this s
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45、959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 03 (2016)3
