1、Designation: C613 97 (Reapproved 2008)2Standard Test Method forConstituent Content of Composite Prepreg by SoxhletExtraction1This standard is issued under the fixed designation C613; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、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.This standard has been approved for use by agencies of the Department of Defense.1NOTEThis standard was corrected to a
3、 single-designation standard editorially in October 2013.2NOTEThe designation of this standard was corrected editorially in November 2013.1. Scope1.1 This test method covers a Soxhlet extraction procedureto determine the matrix content, reinforcement content, andfiller content of composite material
4、prepreg. Volatiles content,if appropriate, and required, is determined by means of TestMethod D3530/D3530M.1.1.1 The reinforcement and filler must be substantiallyinsoluble in the selected extraction reagent and any filler mustbe capable of being separated from the reinforcement byfiltering the extr
5、action residue.1.1.2 Reinforcement and filler content test results are totalreinforcement content and total filler content; hybrid materialsystems with more than one type of either reinforcement orfiller cannot be distinguished.1.2 This test method focuses on thermosetting matrix ma-terial systems f
6、or which the matrix may be extracted by anorganic solvent. However, other, unspecified, reagents may beused with this test method to extract other matrix material typesfor the same purposes.1.3 Alternate techniques for determining matrix and rein-forcement content include Test Methods D3171 (matrixd
7、igestion), D2584 (matrix burn-off/ignition), and D3529/D3529M (matrix dissolution). Test Method D2584 is preferredfor reinforcement materials, such as glass, quartz, or silica, thatare unaffected by high-temperature environments.1.4 The values stated in SI units are to be regarded asstandard.1.5 Thi
8、s standard 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-tiona
9、ry statements are given in Section 9 and 7.2.3 and 8.2.1.2. Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD2584 Test Method for Ignition Loss of Cured ReinforcedResinsD3171 Test Methods for Constituent Content of CompositeMaterialsD3529/D3529M Test Method for Matrix So
10、lids Content andMatrix Content of Composite PrepregD3530/D3530M Test Method for Volatiles Content of Com-posite Material PrepregD3878 Terminology for Composite MaterialsE122 Practice for Calculating Sample Size to Estimate, WithSpecified Precision, the Average for a Characteristic of aLot or Process
11、E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE1309 Guide for Identification of Fiber-ReinforcedPolymer-Matrix Composite Materials in DatabasesE1471 Guide for Identification of Fibers, Fillers, and CoreMaterials in Compute
12、rized Material Property Databases2.2 NFPA Standard:NFPA 86 Standard for Ovens and Furnaces33. Terminology3.1 DefinitionsTerminology D3878 defines terms relatingto composite materials. Terminology D883 defines termsrelating to plastics. Terminology E456 and Practice E1771This test method is under the
13、 jurisdiction of ASTM Committee D30 onComposite Materialsand is the direct responsibility of Subcommittee D30.03 onConstituent/Precursor Properties.Current edition approved March 1, 2008. Published April 2008. Originallyapproved in 1967. Last previous edition approved in 2003 as C613 97(2003)1.DOI:
14、10.1520/C0613_C0613M-97R08E02.2For 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.3Available from National Fire P
15、rotection Association (NFPA), 1 BatterymarchPark, Quincy, MA 02269-9101.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1define terms relating to statistics. In the event of a conflictbetween terms, Terminology D3878 shall have precede
16、nceover the other documents.3.1.1 matrix content, nthe amount of matrix present in acomposite or prepreg expressed either as percent by weight orpercent by volume. For polymer matrix composites this is resincontent. D38783.1.2 prepreg, nthe admixture of fibrous reinforcementand polymeric matrix used
17、 to fabricate composite materials. Itsform may be sheet, tape, or tow. For thermosetting matrices ithas been partially cured to a controlled viscosity called “Bstage”. D38783.1.3 resin content, nsee matrix content. D38783.1.4 sample, na small part or portion of a material orproduct intended to be re
18、presentative of the whole. D8833.1.5 test result, nthe value obtained for a given propertyfrom one test unit.43.1.5.1 DiscussionA test result may be a single observa-tion or a combination of a number of observations when two ormore test specimens are measured for each test.3.1.6 test specimen, na te
19、st unit or portion of a test unitupon which a single or multiple observation is to be made.43.1.7 test unit, na unit or portion of a material that issufficient to obtain a test result(s) for the property or propertiesto be measured.3.1.7.1 DiscussionA test unit may be a subunit of aprimary (first st
20、age) sampling unit or it may be a subunit of acomposite of primary sampling units or of increments fromthese primary sampling units.3.2 Definitions of Terms Specific to This Standard:3.2.1 dry resin content, nprepreg resin content calculatedby subtracting the average mass loss due to volatiles from
21、theinitial test specimen mass.3.2.2 filler content, nthe amount of filler present in aprepreg or composite expressed either as percent by weight orpercent by volume.3.2.2.1 DiscussionIn this test method the reinforcement isseparated from the remainder of the material, which includesthe matrix and th
22、e filler. If the filler is not then separated fromthe matrix to determine the proportion of each, then the fillercontent is included in the matrix content.3.2.3 reinforcement content, nthe amount of reinforce-ment present in a composite or prepreg expressed either aspercent by weight or percent by v
23、olume. This is sometimesstated as a fraction, that is, reinforcement volume fraction.3.2.4 replicate, na test specimen tested under nominallyidentical conditions as other test specimens from the samesample.3.2.5 volatiles content, nthe amount of volatiles present ina prepreg expressed as percent by
24、weight.3.2.6 wet resin content, nprepreg resin content determinedby considering volatiles as part of the resin mass.3.3 Symbols:3.3.1 Ainitial mass of dry reinforcement during a reagentexposure evaluation.3.3.2 Bfinal mass of dry reinforcement during a reagentexposure evaluation.3.3.3 cpercent reinf
25、orcement mass change due to reagentexposure.3.3.4 CVcoefficient of variation statistic of a samplepopulation for a given property.3.3.5 Maadditional mass of filler in the test specimen.3.3.6 Memass of the test specimen extraction residue.3.3.7 Miinitial mass of the test specimen.3.3.8 Mrmass of rein
26、forcement in the test specimen.3.3.9 nnumber of replicates in the sample population.3.3.10 sn1standard deviation statistic of a sample popu-lation for a given property.3.3.11 Wfweight percent of filler in prepreg.3.3.12 Wmweight percent of matrix in prepreg.3.3.13 Wrweight percent of reinforcement i
27、n prepreg.3.3.14 xitest result for an individual test specimen fromthe sample population for a given property.3.3.15 xaverage value of a sample population for a givenproperty.4. Summary of Test Method4.1 The exposed surface area of the prepreg material testspecimen is increased by cutting the test s
28、pecimen into smallerpieces. The test specimen is weighed and the matrix materialremoved by means of Soxhlet extraction. The extracted residueis dried and weighed. If a filler is present in the residue, inaddition to reinforcement, the two components are separatedby filtering the residue. From mass m
29、easurements of the initialtest specimen, and of the residue taken at various stages in theprocess, the matrix content, reinforcement content, and fillercontent are calculated and reported in weight percent.4.1.1 Soxhlet ProcessWhile described in detail in com-mon quantitative chemical analysis textb
30、ooks, the Soxhletprocess is summarized as follows. The test specimen is loadedinto a filtering extraction thimble, which is placed into theextraction chamber of a Soxhlet extraction assembly (see Fig.1) containing an appropriate extraction reagent. The porousthimble allows the liquid extraction reag
31、ent to pass whileretaining the test specimen. Freshly distilled liquid reagententers from the top of the extraction chamber, filling it until theliquid reaches the highest level of the reagent-return tube. Atthis moment the tube operates as a siphon, draining theextraction chamber completely as it r
32、eturns the liquid reagentand any extracted material to a reservoir beneath the extractionchamber. The heated reservoir boils the reagent, the vapor ofwhich is led to a condenser placed above the extractionchamber. The distilled condensate then drips down into thethimble, starting once again the proc
33、ess of filling the extractionchamber. The Soxhlet operation is not a continuous operation,but rather a sequence of fillings and siphonings, each cycle ofwhich is called a reflux change. The heat input and reagentvolume are adjusted to cause the boiling reagent to return to the4See Form and Style for
34、 ASTM Standards.C613 97 (2008)22extraction flask from the condenser at 3 to 10 reflux changesper hour, with the extraction continuing for a minimum of 4 hor 20 reflux changes, whichever comes first.4.1.2 Volatiles ContentVolatiles content is primarily ap-plicable to thermosetting materials, and, if
35、required, is deter-mined by Test Method D3530/D3530M. Volatiles contentdetermination requires different test specimens than those usedin the extraction process, since the process of determiningvolatiles content renders thermosetting material specimensunsuitable for subsequent organic solvent extract
36、ion.5. Significance and Use5.1 The prepreg volatiles content, matrix content, reinforce-ment content, and filler content of composite prepreg materialsare used to control material manufacture and subsequentfabrication processes, and are key parameters in the specifica-tion and production of such mat
37、erials, as well as in thefabrication of products made with such materials.5.2 The extraction products resulting from this test method(the extract, the residue, or both) can be analyzed to assesschemical composition and degree of purity.6. Interferences6.1 Extent of Cure in Thermosetting SystemsThe e
38、ffi-ciency of extraction for thermosetting matrix materials isdirectly related to the extent of cure of the resin system. Resinsthat have started to cross-link (such as B-staged resins) will beincreasingly more difficult to extract as the cure advances. Thistest method may not be appropriate for suc
39、h materials; TestMethods D3171 or D2584 may be better test method choices.6.2 Reagent SelectionThe proper reagent, in a suitablequantity, must be selected for the constituents under test. Thereagents listed in Section 8 are provided for consideration,particularly with regard to thermosetting materia
40、ls, but cannotbe assured to perform well on all material systems within thescope of this test method.6.3 Thimble ContaminationIf the extract is to undergofurther analysis, the thimble must be clean to avoid a signifi-cant source of contamination.6.4 Reinforcement Mass Change As a Result of ReagentTh
41、e calculations of this test method assume that the reinforce-ment mass (or filler, if filler content is being determined) is notsignificantly affected (whether mass increase or mass loss) byexposure to the reagent. Small, consistent changes in thereinforcement mass caused by exposure to the reagent
42、can becorrected by the process described in 14.4.5. The resultingcorrection may be used if this change is sufficiently reproduc-ible under the conditions of the test, and if this change has thesame value for the reinforcement alone as for the reinforcementin the matrix. Otherwise, a different reagen
43、t, or another testmethod, must be selected.7. Apparatus7.1 General Requirements:7.1.1 Container VolumeA suggested volume is shown foreach container. However, other sizes may be required depend-ing upon the test specimen size, the amount of reagent neededto complete the extraction process, and the re
44、lative sizes ofrelated equipment.7.1.2 Thermal ShockLaboratory equipment that is sub-jected to non-ambient temperatures (hot or cold) shall be oftempered-glass or PTFE materials.7.1.3 Post-Test Elemental AnalysisIf a post-test elementalanalysis of the extract or residue is to be performed, laborator
45、yequipment contacting the test specimen shall be constructed ofPTFE and test specimen cutting shall be limited to tools that donot leave an elemental trace.7.2 General Equipment:7.2.1 Analytical BalanceThe analytical balance shall becapable of reading to within 60.1 mg.7.2.2 Muffle FurnaceThe muffle
46、 furnace used to conditionglass extraction thimbles shall be capable of maintaining atemperature of 510 6 15C.7.2.3 Air-Circulating Drying OvenThe drying oven shallbe capable of maintaining a temperature of 163 6 3C.(WarningFor safety purposes listed in NFPA86, take care tolimit volatile concentrati
47、on in the oven by controlling samplequantity, temperature, and ventilation.)7.2.4 DesiccatorThe desiccator shall be capable of con-taining the required test specimens.7.3 Extraction Assembly:7.3.1 Extraction ThimblesThe extraction thimbles shall bedeep, narrow filtering cups, of either borosilicate
48、glass in anappropriate pore size, or fat-extracted cellulose paper, suitablefor use in the extraction chamber.7.3.2 Hot PlateThe hot plate shall have adjustable con-trols suitable for heating the reagent within the reservoir flaskto 260C and shall be capable of controlling the requiredreagent temper
49、ature within 615C.7.3.3 Reservoir FlaskThe reservoir flask shall be of boro-silicate glass, of suitable volume (125 mL is suggested) for thereagent quantity and extraction chamber volume, and shallhave a ground tapered joint capable of connection with theremainder of the assembly.7.3.4 Soxhlet Extraction ChamberThe extraction chambershall be of borosilicate glass, with an automatic recyclingsiphon that recycles at a suitable liquid volume (50 mL isFIG. 1 Schematic of Soxhlet Extraction ApparatusC613 97 (2008)23suggest
