1、Designation: D 5596 03 (Reapproved 2009)Standard Test Method ForMicroscopic Evaluation of the Dispersion of Carbon Blackin Polyolefin Geosynthetics1This standard is issued under the fixed designation D 5596; the number immediately following the designation indicates the year oforiginal adoption or,
2、in 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 procedur
3、es 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 di
4、s-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 i
5、s 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 dis
6、tributionof carbon black.2. Referenced Documents2.1 ASTM Standards:2D 883 Terminology Relating to PlasticsD 3053 Terminology Relating to Carbon BlackD 4439 Terminology for GeosyntheticsE7 Terminology Relating to Metallography3. Terminology3.1 Definitions:3.1.1 carbon black, na material consisting es
7、sentially 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. (D 3053)3.1.2 carbon black agglomerate, na cluster of physicallybound and entangled aggregat
8、es. (D 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. (D 4439)3.1.4 micrograph, na graphic reproduction of an object asseen
9、 through the microscope or equivalent optical instrument,at magnifications greater than ten diameters (micrograph).(E7)3.1.5 microtome, n (that is, sliding microtome)an appara-tus capable of cutting thin slices (less than 20 m in thickness)of various geosynthetic samples.3.1.6 polyolefin, na polymer
10、 prepared by the polymeriza-tion of an olefin(s) as the sole monomer(s). (D 883)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 microse
11、ctioned 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 PreparationA sample isclamped in the sample holder, which can be raised or loweredprecisely in increments of approximately 1 m
12、.Arigid 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 disp
13、ersion 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
14、 ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.02 on Endur-ance Properties.Current edition approved June 1, 2009. Published July 2009. Originally approvedin 1994. Last previous edition approved in 2003 as D 5596 03.2For referenced ASTM standards, visit the A
15、STM 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Uni
16、ted States.throughout 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, stiffness (hardness), or ela
17、sticity 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 micro-tome specimens be c
18、ut 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 besuitable.6.2 Microtome Accesso
19、riesLubricant, 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 103 wide field eyepieces andobjectives in the range
20、 of 5 to 203. Taking into accountmicroscope tube corrections, objectives should be selected sothat final magnifications in the range of 50 to 2003 areavailable.6.4 Microscope AccessoriesA calibrated reticle (eyepiecemicrometer) positioned in one of the eyepieces between theeyepiece-lens and the obje
21、ctive 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 (for ex-ample, clear nail polish), required (Note 2).NOTE 2This clear, adhesive medium should not disso
22、lve or chemi-cally 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 marks. Measure 3.2
23、mm 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 the randomfield
24、 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) for each geosynth
25、eticmaterial 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 of geocomposite
26、samples 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 use of tetrafluo
27、roethane 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.NOTE 4Some extremely flexible or elastomeric materials (e.g., veryFIG
28、. 1 Microscope Cover Slide Overlay ConfigurationD 5596 03 (2009)2flexible 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 for approximate
29、ly 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 tetrafluoroethane befor
30、e 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 from major defec
31、ts 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 5Because thin
32、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 to the blade,
33、make it easier to slide off the blade andonto the slide glass.7.3.1 Mount five (5) specimens to each slide. Place themicroscope cover slide over the five specimens. The coverslide should be placed so that there is a viewing area of eachspecimen. The part of the specimens that is exposed by the two(2
34、) parallel 3.2 mm viewing area of cover slide is consideredthe random 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 slide (a
35、s 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 themicroscope cover
36、 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) micro-scop
37、ically, and locate the largest carbon agglomerate or inclu-sion. If the microscope is not at 1003, select the objective thatallows for viewing at 1003. Calculate the area of the agglom-erate or inclusion. Non-spherical agglomerates calculation ismade by diametric area of best fit.7.8 IterationRepeat
38、 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 pos
39、ition, additional specimens must be prepared to meet theten-reading requirement.7.9 Record all ten (10) readings (calculation) obtained andexpress 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, a
40、nd 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 Bi
41、asNo 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
42、standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years
43、 andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committe
44、e, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,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).D 5596 03 (2009)3
