ASTM D3529-16(2021)
(Test Method)Standard Test Methods for Constituent Content of Composite Prepreg
Standard Test Methods for Constituent Content of Composite Prepreg
SIGNIFICANCE AND USE
5.1 This test method can be used to obtain the fiber content, fiber areal weight, matrix content or matrix solids content. Knowledge of these results is useful in specifying material systems and in developing optimum manufacturing processes. Where volatiles content is consistent and not critical to process, matrix content shall be used.
5.2 This test method is limited to reinforcement constituents that do not change mass upon exposure to the matrix removal procedure and limited to matrix constituents that are fully removed by the matrix removal procedure. In the event of experiencing either limitation, an agreement should be reached with the end-user as to how to proceed.
SCOPE
1.1 This test method covers the determination of the fiber content, fiber areal weight, matrix solids content and matrix content of composite material prepregs. Optionally, the matrix solids content can also be determined after a volatiles content has been established. Volatiles content, if appropriate and required, is determined by means of Test Method D3530.
1.2 Procedure A of this test method applies to composite prepreg of primarily thermosetting matrices that can be extracted in organic solvent. The reinforcement and filler must be substantially insoluble in the selected extraction reagent. This procedure may also be used for the same purposes to extract other matrix material types.
1.3 Procedure B of this test method uses ignition loss of a composite prepreg matrix and applies to organic matrix composite systems containing reinforcing fibers that do not change mass when exposed to the matrix combustion method.
1.4 This test method assumes a two-part material system (plus volatiles) and does not distinguish between hybrid reinforcements or matrices. Use with hybrid composites is limited to determination of total reinforcement or total matrix content.
1.5 Matrix solids determination for Procedures A or B uses Test Method D3530 to determine volatiles content.
1.6 Alternate techniques for determining constituent content include Test Methods C613 (resin content by Soxhlet extraction) and D3171 (used principally for consolidated laminates).
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary information is given in Sections 8 and 9.
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D3529 − 16 (Reapproved 2021)
Standard Test Methods for
Constituent Content of Composite Prepreg
This standard is issued under the fixed designation D3529; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope mine the applicability of regulatory limitations prior to use.
SpecificprecautionaryinformationisgiveninSections8and9.
1.1 This test method covers the determination of the fiber
1.9 This international standard was developed in accor-
content, fiber areal weight, matrix solids content and matrix
dance with internationally recognized principles on standard-
content of composite material prepregs. Optionally, the matrix
ization established in the Decision on Principles for the
solids content can also be determined after a volatiles content
Development of International Standards, Guides and Recom-
has been established. Volatiles content, if appropriate and
mendations issued by the World Trade Organization Technical
required, is determined by means of Test Method D3530.
Barriers to Trade (TBT) Committee.
1.2 Procedure A of this test method applies to composite
prepreg of primarily thermosetting matrices that can be ex- 2. Referenced Documents
tractedinorganicsolvent.Thereinforcementandfillermustbe
2.1 ASTM Standards:
substantially insoluble in the selected extraction reagent. This
C613Test Method for Constituent Content of Composite
procedure may also be used for the same purposes to extract
Prepreg by Soxhlet Extraction
other matrix material types.
D883Terminology Relating to Plastics
1.3 Procedure B of this test method uses ignition loss of a
D3171Test Methods for Constituent Content of Composite
composite prepreg matrix and applies to organic matrix com- Materials
posite systems containing reinforcing fibers that do not change
D3530Test Method for Volatiles Content of Composite
mass when exposed to the matrix combustion method. Material Prepreg
D3878Terminology for Composite Materials
1.4 This test method assumes a two-part material system
E177Practice for Use of the Terms Precision and Bias in
(plus volatiles) and does not distinguish between hybrid
ASTM Test Methods
reinforcements or matrices. Use with hybrid composites is
2.2 NFPA Standard:
limited to determination of total reinforcement or total matrix
NFPA 86Standard for Ovens and Furnaces
content.
1.5 Matrix solids determination for ProceduresAor B uses
3. Terminology
Test Method D3530 to determine volatiles content.
3.1 Definitions—Terminology D3878 defines terms relating
1.6 Alternatetechniquesfordeterminingconstituentcontent
to composite materials. Terminology D883 defines terms
include Test Methods C613 (resin content by Soxhlet extrac-
relating to plastics. Practice E177 defines terms relating to
tion) and D3171 (used principally for consolidated laminates).
statistics.Intheeventofaconflictbetweenterms,Terminology
D3878 shall have precedence over the other documents.
1.7 The values stated in SI units are to be regarded as
3.1.1 fiber content, n—the amount of fiber present in a
standard. No other units of measurement are included in this
composite or prepreg expressed either as percent by weight or
standard.
percent by volume. This is sometimes stated as a fraction, that
1.8 This standard does not purport to address all of the
is, fiber volume fraction. See Terminology D3878.
safety concerns, if any, associated with its use. It is the
3.1.2 matrix content, n—the amount of matrix present in a
responsibility of the user of this standard to establish appro-
composite or prepreg expressed either as percent by weight or
priate safety, health, and environmental practices and deter-
1 2
This test method is under the jurisdiction of ASTM Committee D30 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Composite Materials and is the direct responsibility of Subcommittee D30.03 on contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Constituent/Precursor Properties. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Sept. 1, 2021. Published October 2021. Originally the ASTM website.
approved in 1976. Last previous edition approved in 2016 as D3529–16. DOI: Available from National Fire Protection Association (NFPA), 1 Batterymarch
10.1520/D3529-16R21. Park, Quincy, MA 02269-9101.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3529 − 16 (2021)
percentbyvolume.Forpolymermatrixcompositesthisisresin procedurethechangeinmassisexpressed,bothmatrixcontent
content. See Terminology D3878. and fiber content, as a percentage of the specimen initial mass.
3.1.3 prepreg, n—the admixture of fibrous reinforcement
4.2 When matrix solids content is requested, adjacent
andpolymericmatrixusedtofabricatecompositematerials.Its
samples are tested for volatiles content according to Test
formmaybesheet,tape,ortow.Forthermosettingresins,ithas
Method D3530. The average mass loss due to volatiles is
been partially cured to a controlled viscosity called “B stage”.
subtracted from the average resin content result and the result
See Terminology D3878.
expressed as a percentage of initial specimen mass as matrix
solids content. The matrix solids content is applicable mainly
3.1.4 reinforcement content, n—the amount of reinforce-
to thermosetting matrices.
ment present in a composite or prepreg expressed either as
percent by weight or percent by volume.
5. Significance and Use
3.1.4.1 Discussion—If fiber is the sole reinforcement, then
5.1 This test method can be used to obtain the fiber content,
fiber content is equal to reinforcement content. See Terminol-
fiber areal weight, matrix content or matrix solids content.
ogy D3878.
Knowledge of these results is useful in specifying material
3.1.5 resin content, n—see matrix content.SeeTerminology
systems and in developing optimum manufacturing processes.
D3878.
Wherevolatilescontentisconsistentandnotcriticaltoprocess,
3.2 Definitions of Terms Specific to This Standard:
matrix content shall be used.
3.2.1 dry resin content, n—a prepreg resin content calcu-
5.2 Thistestmethodislimitedtoreinforcementconstituents
latedbysubtractingtheaveragemasslossduetovolatilesfrom
that do not change mass upon exposure to the matrix removal
the initial test mass.
procedure and limited to matrix constituents that are fully
3.2.2 fiber areal weight, n—the mass per unit area of the
removed by the matrix removal procedure. In the event of
fiberous reinforcement of a composite material.
experiencingeitherlimitation,anagreementshouldbereached
3.2.3 matrix solids content, n—see dry resin content. with the end-user as to how to proceed.
3.2.4 wet resin content, n—a prepreg resin content that
6. Interferences
includesanyvolatilespresentintheuncuredresin.Thistermis
6.1 Procedure A:
used interchangeably with matrix content and resin content in
6.1.1 Extent of Cure in Thermosetting Systems—In Proce-
this test method.
dure A, the efficiency of matrix dissolution for thermosetting
3.2.5 volatiles content, n—theamountofvolatilespresentin
matrix materials is directly related to the extent of cure of the
a prepreg expressed as percent by weight.
resin system. A resin that has started to cross link (such as
B-stagedresins)willbeincreasinglymoredifficulttoextractas
3.3 Symbols:
3.3.1 A—specimen area, m . thecureadvances.IfProcedureAisineffectiveinremovingthe
matrix, and Procedure B is inappropriate for the fiber, then
3.3.2 FAW—fiber areal weight; the fiber mass, W , divided
f
anothertestmethod,suchasoneofthemethodsofTestMethod
by the specimen area, A,ing/m .
D3171, should be consulted.
3.3.3 FC—fiber content of specimen, weight percent.
6.1.2 Reagent Selection—The proper reagent, in a suitable
3.3.4 M —mass of container, g.
c quantity, must be selected for the constituents under test. The
3.3.5 MC—matrix content of specimen, weight percent. reagents listed in Section 8 are provided for consideration,
particularly with regard to thermosetting materials, but cannot
3.3.6 M—final mass of specimen and container at end of
f
be assured to perform well on all material systems within the
test, g.
scope of this test method.
3.3.7 M —initial mass of the specimen, g.
I
6.1.3 Ability of Solvent to Reach Matrix—Solventsaremore
3.3.8 MS—matrix solids content of specimen, weight per-
efficient if the material is spread as a film, rather than a solid
cent.
mass. It is recommended that the sample be consolidated as
little as possible before introduction into the solvent.Asolvent
3.3.9 V —average volatiles content test result from Test
c
that is satisfactory for a given form may not be adequate with
Method D3530, weight percent.
the same material of a different form.
4. Summary of Test Methods 6.1.4 Solvent Strength—Solvent strength, or the ability to
rapidlydissolvethematrix,maybeenhancedbyincreasingthe
4.1 Prepreg is sampled and specimens of a specific area are
amount of solvent, increasing agitation, increasing
weighedandthematrixremovedbyappropriateprocedure.For
temperature,orbyplacingthesampleundervacuum.Theseare
ProcedureA, the specimen is subjected to suitable solvent that
offered as physical alternatives to use of more hazardous
affectsthematrix(butnotthereinforcement)untilthematrixis
solvents, or combined solvent systems.
dissolved and removed. The remaining reinforcement is then
dried and weighed. For Procedure B, the specimen is placed in 6.2 Procedure B:
a muffle furnace for a specific time and at a specific tempera- 6.2.1 ApplicabilityofIgnitionLossApproach—InProcedure
ture (at which the reinforcement remains essentially un- B a reinforced resin matrix composite specimen will be
changed) until the matrix can be entirely removed as ash exposed to a temperature in excess of 500°C in an air
residue. The remaining reinforcement is weighed. For either environment for up to 6 h. This test method does not provide
D3529 − 16 (2021)
a measure of resin content for samples containing reinforcing 7.5.1 Crucible—Porcelain, or equivalent properties, with a
materials that lose weight under the conditions of the test or capacity sufficient to completely contain the specimen.
contain resins or fillers that do not decompose to volatile 7.5.2 Electric Furnace—Muffle design capable of maintain-
materials released by ignition. ing 565°C +/- 30°C for burn-out of the resin matrix.
6.2.2 Length of Test—The sample type and configuration 7.5.3 Laboratory Desiccator—Design for pre- and post-test
will determine the length of test exposure. The products of conditioning of the specimen and crucible.
matrix combustion will disappear more readily in configura- 7.5.4 Bunsen Flame—A source of a controlled heat flame
tionshavingalargesurfaceareaofresinmatrixexposuretothe for pre-ignition of the specimen.
oxidizing atmosphere. 7.5.5 Laboratory Safety Equipment—Heatproof gloves and
6.2.3 Pre-Ignition—Provision is made in this standard for protective eyewear are specifically recommended. Laboratory
pre-ignition of the specimen and crucible using a Bunsen exhaust fan and/or ventilation system should be available for
flame. This step may be helpful to flash-off volatiles and use.
initiation of the burning process, but care should be taken to
prevent mechanical loss of sample residue. 8. Reagents
6.2.4 Residual Resin Combustion Products—Fiber residue
8.1 Purity of Reagents—As a minimum, a technical-grade
shouldbecarefullyexaminedforthepresenceofadherentresin
reagent is required to provide accurate results.Areagent-grade
combustion product before determining the final fiber mass
reagent will be used when resolving disputes or performing
(W). If significant amounts of resin product remain on fiber
f
subsequent analysis of extract or residue. Unless otherwise
(“producing a false indication of fiber content”) surfaces, the
indicated,thereagentshallconformtothespecificationsofthe
test method should be repeated. Care should be taken during
Committee onAnalytical Reagents of theAmerican Chemical
this process to assure that no physical loss in fiber content 4
Society, where such specifications are available.
occurs.
8.2 Matrix Dissolution Solvents—Asuitablesolventshallbe
selected that is compatible with the material system under test
7. Apparatus
and the apparatus. Read and understand the precautions listed
7.1 Cutting (Grooved) Template or Die—Thespecimenarea
in Section 9 before selecting a matrix dissolution solvent.
shall be produced with either a cutting templates or a cutting
Matrix dissolution solvents found effective for many thermo-
die. The cutting template or die shall be designed to produce
setting matrices include the following:
the nominal specimen area and shall be capable of limiting the
8.2.1 Acetone (2-Propanone), CH COCH .
3 3
error in area to no more than 62%.
8.2.2 1,2 Methyl Pyrrolidinone (NMP), CH NOC H .
3 3 6
8.2.3 Methyl Ethyl Ketone (MEK, 2-Butanone),
NOTE 1—Attainment of 2% area accuracy with a cutting template and
a single-edge blade requires that average cut be made within 0.4 mm of CH COC H .
3 2 5
the nominal line.Acutting die is preferred over a cutting template and is
8.2.4 Dimethylformamide (DMF), (CH ) NCHO.
3 2
typically capable of providing a cut area error of less than 0.05 %.
(Warning—Asoftheapprovaldateofthisstandard,DMFwas
7.2 Analytical Balance—The analytical balance shall be
listed by the International Agency for Research on Cancer in
capable of reading to within 61 mg.
Group 3 as “not classifiable as to its carcinogenicity to
humans”andisconsideredareproductivetoxinbytheNational
7.3 Timer, accurate to nearest minute.
Toxicology Program. See a recent DMF safety data sheet for
7.4 Procedure A:
more information.)
7.4.1 Fume Exhaust Hood,
8.2.5 Dichloromethane (MECL, methylene chloride),
7.4.2 Containers (Beakers, Flasks)—borosilicate or suitable
CH Cl . (Warning—As of the approval date of this standard,
2 2
plastic that is not dissolved by solvent. The container shall be
MECLwas listed by the InternationalAgency for Research on
ofasuitablevolumeforthesampleandsolvent(aminimumof
Cancer in Group 2B as a “possible human carcinogen.”)
250mLissuggested).Othersizesofcontainermayberequired
8.2.6 Methyl Isobutyl Ketone (MIBK, 4-Methyl-2-
depending on sample size, and amount of solvent needed
...
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