1、Designation: D 5596 03Standard 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, in the case of rev
2、ision, the year 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.1. Scope1.1 This test method covers equipment, specimen prepara-tion techniques, and procedures for evaluating
3、 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-persion size ca
4、lculated 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 theresponsibili
5、ty 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 distributionof carbo
6、n black.2. Referenced Documents2.1 ASTM Standards:D 883 Terminology Relating to Plastics2D 3053 Terminology Relating to Carbon Black3D 4439 Terminology for Geotextiles4E 7 Terminology Relating to Metallography52.2 ASTM Adjuncts: ASTMD 35Carbon Dispersion Reference Chart63. Terminology3.1 Definitions
7、:3.1.1 carbon black, na material consisting essentially 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 clu
8、ster of physicallybound and entangled aggregates. (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 micrograp
9、h, na graphic reproduction of an object asseen through the microscope or equivalent optical instrument,at magnifications greater than ten diameters (micrograph).(E 7)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 ge
10、osynthetic samples.3.1.6 polyolefin, na polymer 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 exist
11、ence of streaks,light or dark, within a microsectioned 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 lowe
12、redprecisely in increments of approximately 1 m. A rigid 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 ran
13、dom field of view (Rf). The1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.02 on Endur-ance Properties.Current edition approved Feb. 10, 2003. Published April 2003. Originallyapproved in 1994. Last previous editio
14、n approved in 1994 as D 559694.2Annual Book of ASTM Standards, Vol 08.01.3Annual Book of ASTM Standards, Vol 09.01.4Annual Book of ASTM Standards, Vol 04.09.5Annual Book of ASTM Standards, Vol 03.01.6Available from ASTM, 100 Barr Harbor Dr., W. Conshohocken, PA 19428,Request PCN: ADJD5596.1Copyright
15、 ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.associated carbon dispersion 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 ultraviole
16、t-induced degradation. Toachieve this, carbon black should be dispersed uniformlythroughout 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
17、 rotary or sledge microtome. Thegeometry, stiffness (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 Extr
18、uded and oriented geogrids will require that micro-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 r
19、ecommended; however, glass knives may besuitable.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
20、should include two 103 wide field eyepieces andobjectives in the range 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) po
21、sitioned in one of the eyepieces between theeyepiece-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 (for ex-ample, clear nail polish)
22、, required (Note 2).NOTE 2This clear, adhesive medium should not dissolve 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 dr
23、aw twoparallel lines the length of the slide at the marks. 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
24、 long as the two (2) 3.2 mmm opening are positioned for therandom field 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
25、randomly acrossthe full roll width (where applicable) for each geosyntheticmaterial to be tested. Geomembrane samples should each beapproximately 2.54 cm 2 (1 in.2). Geonet samples are selectedrandomly from five strands across the full roll width. Geogridsamples are selected randomly from five nodes
26、 across the fullroll width. Pipe and polyolefin components of geocompositesamples are also selected at random.7.2 Specimen PreparationUsing a microtome, prepareone microsection in the cross-machine direction from eachFIG. 1 Microscope Cover Slide Overlay ConfigurationD5596032geomembrane specimen (Se
27、e Note 2). Non-oriented geosyn-thetics material specimens can be prepared without regard toprocessing direction. The use of tetrafluoroethane stiffen spraywill assist microtoming of most materials preventing smearingof carbon black or other constituents in sample. The tetrafluo-roethane spray is use
28、d to stiffen the sample to 15 C beforemicrotoming the specimens.NOTE 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 sam
29、ple clamp can be loosely packed in crusheddry ice 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. Th
30、e sample can bestiffened by spraying with tetrafluoroethane 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
31、be examined easily during microscopy and(2) free from 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
32、slide, using a suitable clear adhesive medium.NOTE 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
33、honing oil on the knife helpsthe specimen to stick to the blade, 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 eac
34、hspecimen. The part of the specimens that is exposed by the two(2) 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 eyepie
35、ce lens and the objective.7.5 Place the microscope cover slide (as shown in Fig. 1) ontop of the mounted thin-sections.7.6 Random Field of View (R f) SelectionBefore attempt-ing any close, microscopic examination of the thin section,place the mounted thin section on the microscope stagepositioned be
36、tween the light source and the objective. Place themicroscope 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 o
37、f viewor Rf.7.7 Microscopic EvaluationExamine each Rfmicroscopi-cally, and locate the largest carbon agglomerate or inclusion. Ifthe microscope is not at 1003, select the objective that allowsfor viewing at 1003. Calculate the area of the agglomerate orinclusion. Non-spherical agglomerates calculati
38、on is made bydiametric area of best fit.7.8 IterationRepeat the procedures given in 7.5 and 7.6until ten readings are recorded. No more than two Rfs 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 ful
39、l random fields of view (Rf) with the glassoverlay in position, 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 ma
40、terial or product tested,including sample type, origin, and 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 p
41、recision of this test method is beingestablished.9.2 BiasNo 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
42、with any item mentionedin this standard. Users of this 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 te
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44、ation at a meeting of theresponsible technical committee, 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
45、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).D5596033
