ISO 16014-4:2012
(Main)Plastics — Determination of average molecular mass and molecular mass distribution of polymers using size-exclusion chromatography — Part 4: High-temperature method
Plastics — Determination of average molecular mass and molecular mass distribution of polymers using size-exclusion chromatography — Part 4: High-temperature method
ISO 16014-4:2012 specifies a method for determining the average molecular mass and the molecular mass distribution of polymers by size-exclusion chromatography (SEC) using an organic eluent at temperatures between 60 °C and 180 °C. The average molecular mass and the molecular mass distribution are calculated from a calibration curve prepared using polymer standards. Therefore, this test method is classified as a relative method.
Plastiques — Détermination de la masse moléculaire moyenne et de la distribution des masses moléculaires de polymères par chromatographie d'exclusion stérique — Partie 4: Mesurage aux températures élevées
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 16014-4
Second edition
2012-07-01
Plastics — Determination of average
molecular mass and molecular mass
distribution of polymers using size-
exclusion chromatography —
Part 4:
High-temperature method
Plastiques — Détermination de la masse moléculaire moyenne
et de la distribution des masses moléculaires des polymères par
chromatographie d’exclusion stérique —
Partie 4: Mesurage aux températures élevées
Reference number
ISO 16014-4:2012(E)
©
ISO 2012
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ISO 16014-4:2012(E)
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ISO 16014-4:2012(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 1
5.1 Eluent . 1
5.2 Reagent for column evaluation . 1
5.3 Molecular mass standards . 2
5.4 Reagent for flow rate marker (internal standard) . 2
5.5 Additives . 2
6 Apparatus . 2
6.1 General . 2
6.2 Eluent reservoir . 2
6.3 Pumping system . 2
6.4 Injector . 2
6.5 Columns . 2
6.6 Detector . 3
6.7 Tubing . 3
6.8 Temperature-control unit . 3
6.9 Recorder and plotter . 3
6.10 Data-processing system . 3
6.11 Other components . 3
7 Procedure . 3
7.1 Preparation of solutions of molecular mass standards . 3
7.2 Preparation of sample solutions . 4
7.3 Preparation of solutions for column performance evaluation . 4
7.4 Setting up the apparatus . 5
7.5 Operating parameters . 5
7.6 Number of determinations . 5
8 Data acquisition and processing . 5
9 Expression of results . 6
10 Precision . 6
10.1 General . 6
10.2 Experimental conditions . 6
10.3 Results of round-robin test . 7
11 Test report . 7
Annex A (informative) Further information on applicability of method . 8
Annex B (informative) Further information on reagents . 9
Annex C (informative) Further information on the round-robin test .10
Bibliography .14
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ISO 16014-4:2012(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. 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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 16014-4 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 5, Physical-
chemical properties.
This second edition cancels and replaces the first edition (ISO 16014-4:2003), which has been technically
revised. The main changes are as follows:
a) the normative references have been updated;
b) Subclause 6.1 (concerning the general requirements for the apparatus) has been revised;
c) further information on the round-robin test carried out in 1999 has been added (see Annex C).
ISO 16014 consists of the following parts, under the general title Plastics — Determination of average molecular
mass and molecular mass distribution of polymers using size-exclusion chromatography:
— Part 1: General principles
— Part 2: Universal calibration method
— Part 3: Low-temperature method
— Part 4: High-temperature method
— Part 5: Method using light-scattering detection
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INTERNATIONAL STANDARD ISO 16014-4:2012(E)
Plastics — Determination of average molecular mass and
molecular mass distribution of polymers using size-exclusion
chromatography —
Part 4:
High-temperature method
1 Scope
This part of ISO 16014 specifies a method for determining the average molecular mass and the molecular mass
distribution of polymers by size-exclusion chromatography (SEC) using an organic eluent at temperatures
between 60 °C and 180 °C. The average molecular mass and the molecular mass distribution are calculated
from a calibration curve prepared using polymer standards. Therefore, this test method is classified as a
relative method (see ISO 16014-1:2012, Annex A).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO 472, Plastics — Vocabulary
ISO 16014-1:2012, Plastics — Determination of average molecular mass and molecular mass distribution of
polymers using size-exclusion chromatography — Part 1: General principles
ISO 16014-2, Plastics — Determination of average molecular mass and molecular mass distribution of polymers
using size-exclusion chromatography — Part 2: Universal calibration method
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472 and in ISO 16014-1 apply.
4 Principle
See ISO 16014-1:2012, Clause 4.
5 Reagents
5.1 Eluent
For a general discussion of eluents, see ISO 16014-1:2012, 5.1.
For examples of eluents used for SEC measurements at temperatures > 60 °C, see Annex B.
5.2 Reagent for column evaluation
See ISO 16014-1:2012, 5.2.
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ISO 16014-4:2012(E)
There are several low molecular mass compounds that can be used, for example diphenylmethane when
1,2-dichlorobenzene is used as eluent or ethylbenzene when 1,2,4-trichlorobenzene is used as eluent.
5.3 Molecular mass standards
See ISO 16014-1:2012, 5.3.
Some examples of commercially available molecular mass standards are given in Annex B.
5.4 Reagent for flow rate marker (internal standard)
See ISO 16014-1:2012, 5.4.
An example of a compound suitable for use as a flow rate marker is 2,6-di-tert-butyl-4-methylphenol when
1,2-dichlorobenzene or 1,2,4-trichlorobenzene is used as eluent.
5.5 Additives
Phenol-type antioxidants such as 2,6-di-tert-butyl-4-methylphenol should preferably be added to avoid
degradation of the polymer sample. For further examples of antioxidants, see Annex B.
6 Apparatus
6.1 General
A schematic diagram of an SEC system is shown in ISO 16014-1:2012, Figure 1.
Either commercially available or assembled SEC systems may be used, provided they meet the component
requirements specified and have the capability to maintain a constant column temperature between 60 °C and
180 °C. However, components connected upstream of the injector, such as the eluent reservoir, the pumping
system and tubing, does not need to be kept at the same temperature as the columns.
6.2 Eluent reservoir
See ISO 16014-1:2012, 6.2.
As mentioned in 6.1, it is not necessary to keep the eluent reservoir at the same temperature as the columns.
6.3 Pumping system
See ISO 16014-1:2012, 6.3.
In order to maintain the flow rate accurate to within ±0,3 %, the pumping system shall be kept at a constant
temperature. As mentioned in 6.1, it is not, however, necessary to keep the pumping system at the same
temperature as the columns.
6.4 Injector
See ISO 16014-1:2012, 6.4.
In order to ensure that the polymer solution remains clear, without any precipitation, the injector temperature-
control equipment shall be capable of keeping the injector at the same temperature, to within ±1 °C, as the
columns. As manual injection is impossible at such temperatures, an automatic injection system shall be used.
6.5 Columns
See ISO 16014-1:2012, 6.5.
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ISO 16014-4:2012(E)
Organic or inorganic packing materials may be used, and there are no limitations on particle size or shape
except that, when analysing high molecular mass and/or shear-sensitive polymers, the particle size should be
large enough for no rupture of the polymer chain to occur during elution of the polymers.
The set of columns used shall have a theoretical plate number > 12 000/m, and the resolution factor R shall be
> 1,5 close to the polymer peak. The asymmetry factor shall be within the range 1,00 ± 0,15. The set of columns
used should preferably cover the whole range of molecular masses being determined, and the calibration curve
shall be as linear as possible (the correlation factor shall be very close to 1). Determination of the theoretical
plate number, the resolution factor and the asymmetry factor of the columns shall be carried out as described
in ISO 16014-1:2012, 6.5.
The column temperature-control equipment shall be capable of keeping the columns within ±0,5 °C of the
operating temperature, which shall be between 60 °C and 180 °C.
6.6 Detector
See ISO 16014-1:2012, 6.6.
The detector temperature-control equipment shall be capable of keeping the detector within ±0,5 °C of
the temperature set, in order to meet the requirements for flow rate and baseline stability (sensitivity). It is
recommended that the columns and detector be kept at the same temperature.
6.7 Tubing
See ISO 16014-1:2012, 6.7.
The temperature of the tubing shall be kept constant and high enough to ensure that the column performance
requirements are met, but it is not necessary to keep the tubing at the same temperature as the column.
6.8 Temperature-control unit
One of the important factors in SEC is that all components need to be kept at a constant temperature and, with
the method described in this part of ISO 16014, some of them need to be kept at a high temperature. Therefore,
an accurate temperature-control system is essential to meet the performance requirements for SEC.
6.9 Recorder and plotter
See ISO 16014-1:2012, 6.9.
6.10 Data-processing system
See ISO 16014-1:2012, 6.10.
6.11 Other components
In addition to the components described above, a column guard filter, a pressure monitor, a pulse damper or
related components can be used, if necessary.
7 Procedure
7.1 Preparation of solutions of molecular mass standards
The molecular mass standards used to prepare the calibration curve should preferably be selected so as
to cover the range of molecular masses of the polymer being analysed and so that there are at least two
standards in each molecular mass decade. Solutions may be prepared which contain more than one narrow
molecular mass
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