SIST EN ISO 307:2000

SLOVENSKI STANDARD
SIST EN ISO 307:2000
01-maj-2000
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Plastics - Polyamides - Determination of viscosity number (ISO 307:1994)
Kunststoffe - Polyamide - Bestimmung der Viskositätszahl (ISO 307:1994)
Plastiques - Polyamides - Détermination de l'indice de viscosité (ISO 307:1994)
Ta slovenski standard je istoveten z: EN ISO 307:1997
ICS:
83.080.20 Plastomeri Thermoplastic materials
SIST EN ISO 307:2000 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 307:2000

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SIST EN ISO 307:2000

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SIST EN ISO 307:2000

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SIST EN ISO 307:2000

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SIST EN ISO 307:2000

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SIST EN ISO 307:2000
ISO
INTERNATIONAL
307
STANDARD
Third edition
1994-09-01
- Polyamides - Determination
Plastics
of viscosity number
- Polyamides - D6 termina tion de I ’indice de viscosite
Plas tiques
Reference number
ISO 307: 1994(E)

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SIST EN ISO 307:2000
ISO 307:1994(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. Esch 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 307 was prepared by Technical Committee
lSO/TC 61, Plastics, Subcommittee SC 9, Thermoplastic materjals.
This third edition cancels and replaces the second edition
(ISO 307:1984), of which it constitutes a technical revision.
Annex A forms an integral patt of this International Standard.
0 ISO 1994
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronie or mechanical, including photocopying and
microfilm, without Permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-l 211 Geneve 20 l Switzerland
Printed in Switzerland
ii

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SIST EN ISO 307:2000
INTERNATIONAL STANDARD 0 ISO ISO 307:1994(E)
- Determination of viscosity
Plastics - Polyamides
number
ISO 472:1988, Plastics - Vocabulaty.
1 Scope
- Polyamide homopolymers
ISO 599: 1985, Plastics
This International Standard specifies a method for the
- Determination of matter extractable by boiling
determination of the viscosity number of dilute sol-
methanol.
utions of polyamides in certain specified solvents.
ISO 960: 1988, Plastics - Polyamides (PA) - Deter-
The method is applicable to the polyamides desig-
mina tion 0 f wa ter content.
nated PA 6, PA 66, PA 69, PA 610, PA 612, PA 11,
PA 12 and PA MXD6 as defined in ISO 1874-1, as
ISO 1042:1983, Laboratory glassware - One-mark
well as to copolyamides and other polyamides that are
volume tric flasks.
soluble in one of the specified solvents under the
specified conditions.
ISO 1628-1: 1984, Guidelines for the standardization
The method is not applicable to polyamides produced of methods for the determination of viscosity number
by anionic polymerization of Iactams or produced with and limiting viscosity number of Polymers in dilute
Solution - Part 1: General conditions.
crosslinking agents; such polyamides are normally in-
soluble in the specified solvents.
- Polyamide (PA) mould-
ISO 1874-1: 1992, Plastics
The viscosity number is determined by the general
ing and extrusion materials - Part 1: Designation.
procedure specified in ISO 1628-1, observing the par-
ticular conditions specified in this International Stan- ISO 3105: -l) Glass capillary kinema tic viscome ters
- Speci fica tions and Opera ting ins tructions.
dard.
The determination of the viscosity number of a
ISO 3451-4:1986, Plastics - Determination of ash -
Polyamide provides a measure of the relative mol-
Part 4: Polyamides.
ecular mass of the polymer.
ISO 6427:1992, Plastics - Determination of matter
extractable by organic solvents (conventional meth-
Ods).
2 Normative references
ASTM D 789:1986, Standard test methods for deter-
The following Standards contain provisions which,
mination of relative viscosity, melting Point, and
through reference in this text, constitute provisions
moisture tonten t o f Polyamide (PA).
of this International Standard. At the time of publi-
cation, the editions indicated were valid. All Standards
are subject to revision, and Parties to agreements
based on this International Standard are encouraged 3 Definitions
to investigate the possibility of applying the most re-
cent editions of the Standards indicated below. For the purposes of this International Standard, the
Members of IEC and ISO maintain registers of cur- definitions given in ISO 1628-1 and the following de-
rently valid International Standards. finition apply.
1) To be published. (Revision of ISO 3105:1976)

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SIST EN ISO 307:2000
ISO 307:1994(E) 0 ISO
3.1 viscosity number (of a polymer): The value 5.1.3 m-Cresol, meeting the following specifi-
given by the formula cations:
appearance: clear and colourless
m-cresol content: 99 % (m/m) min.
where
o-cresol content: 0,3 % (m/m) max.
is the viscosity of a Solution of the polymer
in a specified solvent;
water content: 0,13 % (m/m) max.
is the viscosity of the solvent, expressed
m-CresoI of the required purity tan be obtained by
in the same units as q;
distillation of chemically pure mcresol, preferably in
vacuo.
is the concentration, in grams per millilitre,
@P
of the polymer in the Solution.
To avoid Oxidation, nitrogen shall preferably be used
for pressure compensation. Its purity may be checked
The viscosity number is usually expressed in millilitres
by gas chromatography. The solvent shall be stored
gram.
Per
in a brown glass bottle.
5.2 Cleaning liquids
4 Principle
5.2.1 Chromic acid Solution, prepared by mixing
The times of flow of a solvent and a Solution of the
equal volumes of sulfuric acid (e = 1,84 g/mI) and a
Polyamide at a concentration of 0,005 g/ml in the sol-
saturated Solution of potassium dichromate. If re-
vent are measured at 25 “C, the same viscometer
quired, the chromic acid solution may be replaced by
being used for both measurements. The viscosity
other, equally effective cleaning liquids.
number is calculated from these measurements and
from the known concentration of the Solution.
5.2.2 Acetone, freshly distilled.
6 Apparatus
5 Reagents and materials
6.1 Vacuum drying cabinet, pressure less than
of recognized analyt
Use only reagents ical grad e and
100 kPa.
only distilled water or water of equivale nt purity
6.2 Balance, accurate to 0,l mg.
WARNING - Avoid contact with the skin and
inhalation of any vapours of the solvents and
cleaning liquids.
6.3 Volumetric flask, capacity 50 ml, complying
with the requirements of ISO 1042, fitted with a
ground-glass stopper.
5.1 Solvents
64 .
Shaking apparatus or magnetic stirrer.
5.1.1 Sulfuric acid, 96 % (m/m) + 0,15 % Im/m) sol-
6.5 Sintered-glass filter, with a pore size between
ution.
40 Pm and 100 Pm (grade P IOO), or stainless-steel
For the determination of the concentration of com-
sieve, with apertures of about 0,075 mm*.
mercial sulfuric acid (95 % to 97 %) and adjustment
to 96,0 %, see annex A.
6.6 Viscometer, of the suspended-level Ubbelohde
type, complying with the requirements of ISO 3105.
The essential dimensions of the viscometer are
5.1.2 Formic acid, 90 % (m/m) + 0,15 % (m/an) sol-
shown in figure 1. For use with the formic acid sol-
ution.
ution (5.1.2), the inside diameter of the capillary shall
The solvent shall be stored in a brown glass bottle. Its be 0,58 mm + 2 % (complying with the requirements
-
concentration shall be checked at least evev of size No. 1 of ISO 3105). For use with the sulfuric
2 weeks. lt shall not contain more than 0,2 % acetic
acid Solution (5.1 .l) or mcresol (5.1.3), the inside di-
acid or methyl formate. ameter of the capillary shall be 1,03 mm + - 2 %
2

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SIST EN ISO 307:2000
0 ISO
ISO 307:1994(E)
(complying with the requirements of size No. 2 of vent to be used, i.e. that it does not form particles of
ISO 3105).
.
w 1
Other types of viscometer listed in ISO 3105 may be The fraction of polymer modifier and other additives
used, provided that the results are equivalent to those that are insoluble in hydrochloric acid is determined
of the Ubbelohde viscometers specified above. How- from the hydrolysis residue (this method will form the
ever, in cases of dispute, an Ubbelohde viscometer subject of a future International Standard) and the
shall be used. correct amount of Polyamide Sample to be weighed
out is calculated using equation 8.2.
6.7 Thermostatic bath, capable of being main-
NOTE 1 Experience indicates that the usual polymer
tained at 25 “C + 0,05 “C.
-
modifiers for polyamides, e.g. ethylene copolymers and EP
rubber, are so finely dispersed in the Solution of the Sample
that the Solution viscosity is practically unaffected, provided
6.8 Stop-watch, accurate to 0,l s.
that the Solution is free from gel particles.
6.9 Centrifuge.
If carbon fibres that tan be detected in the hydrolysis
residue under an Optical microscope are present, they
shall be filtered off from the Solution of the Polyamide
7 Preparation of test samples
Sample by means of a filter crucible with a glass frit.
7.1 General
7.4 Samples with auxiliaries that are soluble
in dilute hydrochloric acid and/or cannot be
Polyamide test samples for the determination of the
determined from the ash owing to Oxide
viscosity number shall be completely soluble in the
formation, e.g. carbonates, metal powders
solvents mentioned, and the additives contained in
and certain Pigments
them (reinforcement fibres, flame-retardants and
modifiers) shall not interfere with the viscosity
The residue on dissolution in 90 % formic acid is de-
measurement, or it shall be possible to separate the
termined as follows:
additives quantitatively from the Solution as with glass
and carbon fibres, for instance.
Shake or stir the Polyamide Sample for several hours
at room temperature in about 10 times its own vol-
If the content of these additives is greater than
ume of 90 % formic acid using the procedure de-
2 % (m/m), it shall be determined quantitatively to al-
scribed in 10.2.
low the exact test Portion size to be calculated (see
table 1).
Separate off the solid residue by filtration.
Exception: an extracted Sample if it contains extract-
Carefully wash the residue with 90 % formic acid and
able additives (see 7.2).
then with acetone. Subsequently dry for 3 h at
100 “C under a vacuum. Weigh.
7.2 Samples with extractable ingredients
7.5 Samples with auxiliaries with
The ground polymer remaining after extraction in ac-
determinable ash, e.g. glass fibres and
cordante with ISO 6427 or ISO 599 shall be dried by
silicates
heating for 3 h at 100 “C under vacuum and used as
the test Sample.
The ash is determined by the method specified in
ISO 3451-4, and the amount of Polyamide Sample to
be weighed out is calculated using equation 8.2.
7.3 Samples with auxiliaries
When necessary, filter the Solution of the Sample
(non-hydrolyzable and without ash) that are
through a filter crucible with a glass frit before making
insoluble in hydrochloric acid, e.g. polymer
the measurement.
modifiers, carbon fibres and certain
flame-retardants
Any glass fibres of the usual dimensions con-
NOTE 2
tained in the Sample will Sediment completely after 3 h to
Preliminary tests shall be carried out to determine
4 h. In such cases, the test Solution tan be decanted for the
whether the Sample is completely soluble in the sol-
measurement and thus does not need to be filtered.

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SIST EN ISO 307:2000
0 ISO
ISO 307:1994(E)
Table 1 - Determination of additives in Polyamide samples in Order to be able to calculate the correct
test Portion size
Additives
Remarks See subclause
Property determined Test method
determinable
7.2
Extractable-matter ISO 6427; ISO 599 Low-molecular-weight Extract Sample before
content fractions measurement (thus
no correction necess-
Plasticizers
at-y to size of test por-
tion)
Stabilizers
Slip agents
Polymer modifiers Check solubility (if 7.3
Hydrolysis residue (no
(e-g. ethylene and E/P necessary, also deter-
ash)
copolymers) mine ash and residue
on dissolution)
Carbon fibres
Organic flame-
retardants
7.4
Residue in 90 % Carbonates
formic acid Solution
Metal powders
(no ash)
Pigments
Organic flame-
retardants
ISO 3451-4 Glass fibres If necessary, increase 7.5
Ash (no Oxide conver-
size of test Portion
sion)
Silicates
Inorganic flame-
retardants
is the content of other materials (for
8 Calculation of mass of test Portion ww3
example other polymers such as
polyolefins, or additives, such as flame-
8.1 Polyamides with extractable matter
retardants), expressed as a percentage
content not greater than 2,00 % (m/m)
by mass, determined by appropriate
methods.
Calculate the mass mc, in milligrams, of the test por-
tion as follows:
The corrections for w(%),, Wo and Wo need
only be applied if they exceed 0,5 % (dm) each.
250
mc =
, w(%), + w(%)* + w(%>3
where
8.2 Polyamides with extractable matter
content greater than 2,00 % (m/.m)
is the water content of the Sample, ex-
ww> 1
pressed as a percentage by mass, de-
Use the material extracted and dried according to 7.3
termined in accordance with ISO 960;
as the test Sample. Calculate the mass mc, in milli-
is the content of inorganic materials (for grams, of the test Portion as follows:
4w2
example fillers or glass fibres) of the
250
mc =
Sample, expressed as a percentage by
w(%)2 + w(%)3
mass, determined in accordance with -
1
100 - w(%)4
ISO 3451-4;

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SIST EN ISO 307:2000
0 ISO
ISO 307:1994(E)
figure 3. The reliability of the conversion is discussed
in
13.2.
m,, w(%)2 and Wo have the same meanings
as in 8.1;
9.4 For PA 11, PA 12 and PA 11/12 copolymers,
m-cresol shall be used as solvent.
is the content of extract-
wv44
able matter of the Sample,
9.5 For other polyamides, any of the three solvents
expressed as a percentage
may be used.
by mass.
lt has been assumed in this calculation that Wo and
10 Procedure
Wo have been determined on the unextracted
Sample and that the extracted and dried material will
10.1 Cleaning of viscometer
be kept dry, so that no correction for moisture in the
test Sample is required.
Clean the viscometer (6.6) Prior to the first use, again
after discordant readings (for example when two
NOTE 3 When dissolved in 50 mI of solvent, a test por-
successive determinations of the efflux time of the
tion weighing exactly mc mg will give a Solution containing
solvent differ more than 0,4 s) and,
...