EN ISO 11667:1999

SLOVENSKI STANDARD
01-maj-2000
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Fibre-reinforced plastics - Moulding compounds and prepregs - Determination of resin,
reinforced-fibre and mineral-filler content - Dissolution methods (ISO 11667:1997)
Faserverstärkte Kunststoffe - Formmassen und Prepregs - Bestimmung des Gehaltes an
Harz, Verstärkungsfaser und Mineralfüllstoff - Auflösungsverfahren (ISO 11667:1997)
Plastiques renforcés de fibre - Préimprégnés et compositions de moulage -
Détermination des taux de résine, de fibre de renfort et de charge minérale - Méthodes
par dissolution (ISO 11667:1997)
Ta slovenski standard je istoveten z: EN ISO 11667:1999
ICS:
83.120 2MDþDQLSROLPHUL Reinforced plastics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 11667
First edition
1997-12-15
Fibre-reinforced plastics — Moulding
compounds and prepregs — Determination
of resin, reinforced-fibre and mineral-filler
content — Dissolution methods
Plastiques renforcés de fibre — Préimprégnés et compositions
de moulage — Détermination des taux de résine, de fibre de renfort et
de charge minérale — Méthodes par dissolution
A
Reference number
ISO 11667:1997(E)
ISO 11667:1997(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide
federation of national standards bodies (ISO member bodies). The work of
preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which
a technical committee has been established has the right to be represented
on that committee. International organizations, governmental and non-
governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard ISO 11667 was prepared by Technical Committee
ISO/TC 61, Plastics, Subcommittee SC 13, Composites and reinforcement
fibres.
Annex A of this International Standard is for information only.
©  ISO 1997
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet central@iso.ch
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Printed in Switzerland
ii
©
INTERNATIONAL STANDARD  ISO ISO 11667:1997(E)
Fibre-reinforced plastics — Moulding compounds and prepregs —
Determination of resin, reinforced-fibre and mineral-filler
content — Dissolution methods
WARNING — Persons using this International Standard should be familiar with normal laboratory practice.
This standard does not purport to address all of the safety problems, if any, associated with its use. It is the
responsibility of the user to establish appropriate safety and health practices and to ensure compliance
with any national regulatory conditions.
1  Scope
This International Standard specifies two dissolution methods for the determination of the resin, reinforcement-fibre
and mineral-filler contents of moulding compounds and prepregs:
Method A: Extraction by Soxhlet. In cases of dispute, this method is the reference method.
Method B: Extraction by immersion in solvent in a beaker. This method uses simpler equipment, making it
suitable for quality assurance testing.
This International Standard is applicable to the following types of material:
— prepregs made from yarns, rovings, tapes and fabrics;
— SMC, BMC and DMC moulding compounds.
Typically, reinforcement fibres are coated with sizing or finishes. These normally dissolve with the resin and are,
therefore, included in the resin content.
This International Standard is not applicable to the following types of reinforced plastic:
— those containing reinforcements which are soluble (or partly soluble) in the solvents used to dissolve the resin;
— those in which the resin is partly or fully cured and so not fully soluble in organic solvents.
NOTE —  ISO 1172:1996, Textile-glass-reinforced plastics — Prepregs, moulding compounds and laminates — Determination
of the textile-glass and mineral-filler content — Calcination methods, may be used where the resin is cured.
2  Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the editions indicated were valid. All standards are subject to
revision, and parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain
registers of currently valid International Standards.
ISO 291:1997, Plastics — Standard atmospheres for conditioning and testing.
©
ISO
ISO 11667:1997(E)
ISO 472:1988, Plastics — Vocabulary.
ISO 4793:1980, Laboratory sintered (fritted) filters — Porosity grading, classification and designation.
3  Definitions
For the purposes of this International Standard, the relevant definitions given in ISO 472 apply, with the following
addition:
3.1  elementary unit
Smallest normally commercially available entity of a given product.
4  Principle
The non-soluble material content (reinforcement fibre + filler) is obtained by the measurement of the difference in
the mass of a test specimen before and after extraction by solvent under defined conditions.
The soluble part (resin) is extracted either in a Soxhlet apparatus (method A) or by immersion in a beaker
(method B).
When the material under test contains fillers, the separation between fibres and fillers is obtained either by reacting
the mineral filler with hydrochloric acid (method A) or by successive filtration without the use of acid (method B).
The masses before dissolution, after dissolution and after reaction with acid or filtration enable the reinforcement,
resin and filler contents to be calculated.
5  Sampling
5.1  The test shall be carried out on two specimens which are as identical as possible. On prepreg fabrics, the
specimens shall be taken at least 50 mm from the edge.
Two test specimens are sufficient providing that the difference between the values obtained is 5 % or less. If this is
not the case, a third specimen shall be tested which is as identical to the other two as possible.
5.2  In order to obtain an evaluation result that is as representative as possible of the resin, reinforcement-fibre and
mineral-filler content of the elementary unit examined, this test procedure may need to be repeated a certain
number of times, at specific places in the elementary unit. The number and location of the tests required should be
defined either in the product specification or by the person requesting the analysis. Alternatively, the number and
location may be decided by prior experience.
5.3  For all tests which are not carried out on elementary units, take test specimens that are as representative of
the material under test as circumstances allow.
6  Preparation of test specimens
Unless otherwise specified, it is recommended that the test specimens be cut in a shape which allows them to fit
into the thimble of the Soxhlet apparatus or the beaker used for the extraction.
The mass should preferably be in the range 2 g to 20 g.
©
ISO
ISO 11667:1997(E)
NOTE —  For SMC, BMC and DMC tested by method B, a larger test specimen may be used if this is more representative of
the material.
In the case of prepregs and moulding compounds which contain solvents or free monomer, care shall be taken to
avoid loss of volatile matter. It is recommended that materials containing free monomer should not be left
unprotected for more than 5 min before commencing the test procedure. For SMC, the protective release film shall
not be remove from the laboratory sample or test specimen until just before commencing the test procedure. All
prepreg and moulding-compound laboratory samples, including SMC, shall be sealed in a vapour-proof plastic bag
immediately after the laboratory sample is taken.
7  Test methods — General
The method used to dissolve the resin depends on the accuracy of the result required by the person ordering the
test. The procedures for separating the reinforcement fibre from the mineral filler are different in the two methods.
The method requires the masses of all specimens to be brought to a constant value by repetition of the drying and
dissolution stages and by reweighing until the difference between two consecutive weighings is less than 1 mg. In
those cases where known materials are being tested regularly, however, it is permitted to define, by
experimentation, minimum times for dissolution and drying, to be certain that constant mass has been reached.
8  Method A: Extraction by Soxhlet
8.1  Reagents
The solvent used shall be capable of completely extracting all the resin from the test specimen.
Solvents suitable for the more common resins include:
dichloromethane;
acetone;
methyl ethyl ketone (butan-2-one);
denatured ethanol.
Other solvents may be used as necessary to achieve complete extraction.
8.2  Apparatus
Normal laboratory equipment, plus the following:
8.2.1  Balance, accurate to 0,5 mg and graduated to 0,1 mg.
8.2.2  Soxhlet extraction apparatus with a thimble large enough to contain the whole of the test specimen.
8.2.3  Cutting tool.
8.2.4  Desiccator, containing a suitable drying agent (e.g. silica gel).
8.2.5  Ventilated drying oven, set at 105 �C – 3 �C.
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ISO 11667:1997(E)
8.3  Procedure
For each test specimen, proceed as follows:
8.3.1  Preparation of extraction thimble
Dry the extraction thimble in the oven (8.2.5) at 105 �C – 3 �C for 1 h.
Cool to room temperature in the desiccator (8.2.4).
Weigh on the balance (8.2.1) to 1 mg. Continue to constant mass (see clause 7) and record the mass, in grams,
as m .
8.3.2  Weighing the test specimen and solvent extraction of the resin
Using the cutting tool (8.2.3), cut the test specimen into pieces of a convenient size and place in the thimble (see
8.2.2), being careful that no fragments are lost. Weigh the whole to the nearest 1 mg. Record the mass, in grams,
as m .
Place the thimble and its contents in the siphon of the extraction apparatus (8.2.2). Fit the condenser, siphon tube
and flask together and add a suitable quantity of methyl ethyl ketone or other suitable solvent (see 8.1), or that
specified in the material specification.
Regulate the heating rate of the mantel so that the siphoning rate is sufficient to achieve complete extraction of the
resin in 1 h.
Carry out the test for this period or as given in the specification for the particular material.
Remove the thimble and contents. Dry in the oven and allow to cool in the desiccator. Weigh to the nearest 1 mg.
Continue to constant mass (see clause 7) and record the mass, in grams, as m .
For materials containing no mineral fillers, the mass m may be used to determine the reinforcement-fibre content.
For materials which contain mineral fillers, the reinforcement fibre and the mineral filler must first be separated,
using the procedure given in 8.4.
8.4  Separation of reinforcement fibre from mineral filler
8.4.1  Reagents
8.4.1.1  Hydrochloric acid, concentration 35 % (V/V), commercial grade.
8.4.1.2  Denatured ethanol.
8.4.1.3  Chromic acid mixture, for cleaning. Recommended composition: 7 g of sodium dichromate in 100 ml of
concentrated sulfuric acid.
8.4.2  Apparatus
The apparatus specified in 8.2, plus the following:
8.4.2.1  Glass rod.
8.4.2.2  Sintered-glass filter, diameter 40 mm, porosity P 160 (100 mm to 160 mm — see ISO 4793).
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ISO 11667:1997(E)
8.4.2.3  250 ml beaker.
8.4.2.4  Filter suction flask.
8.4.2.5  Tweezers.
8.4.3  Procedure
For each test specimen, proceed as follows:
8.4.3.1  Preparation of sintered-glass filter
Before the test, clean each filter (8.4.2.2) by soaking in chromic acid mixture (8.4.1.3). Then rinse with warm water
followed by denatured alcohol (8.4.1.2). Place the filter on the filter suction flask (8.4.2.4) and apply suction. Place
the filter in the oven at 105 �C – 3 �C until constant mass is reached (see clause 7). Record the mass, in grams,
as m .
8.4.3.2  Separation of the reinforcement fibre from the mineral filler when the mineral filler completely
dissolves in hydrochloric acid
Place in the 250 ml beaker (8.4.2.3) 5 ml of hydrochloric acid per gram of residue remaining after dissolution of the
resin.
Using the glass rod (8.4.2.1), slowly add the residue to the acid in the beaker. Stir carefully to ensure that all the
residue has reacted with the acid, assuring that the bubbling caused by the acid reacting with the carbonate fillers
does not cause splashing.
When the bubbling has finished, rinse the thimble with water, pouring the washings into the 250 ml beaker. Repeat,
if necessary, until all the residue has been transferred to the beaker.
Add an additional 50 ml of water to the beaker.
Place the filter, which has been previously dried and weighed (mass m ), on the suction flask and apply suction.
Slowly pour the supernatant acid in the beaker on to the filter.
Rinse the reinforcement fibre left in the beaker with water, pouring the washings on to the filter, then rinse with
denatured ethanol while agitating with the glass rod. Pour this ethanol on to
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