ISO 24076:2021

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 24076
ISO/TC 61/SC 9
Plastics — Polypropylene (PP) —
Secretariat: KATS
Determination of isotactic index by
Voting begins on:
2020­11­03 low-resolution nuclear magnetic
resonance spectrometry
Voting terminates on:
2020­12­29
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ISO/FDIS 24076:2020(E)
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NATIONAL REGULATIONS. ISO 2020

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ISO/FDIS 24076:2020(E)

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ISO/FDIS 24076:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 2
6 Preparation of sample . 2
6.1 General . 2
6.2 Reference samples . 2
7 Method A — Ratio method . 2
7.1 Procedure . 2
7.1.1 Measurement of reference samples by n-heptane extraction . 2
7.1.2 LR­NMR measurement procedure of reference samples . 3
7.1.3 LR­NMR measurement procedure of test samples . 3
7.2 Calculation . 3
7.2.1 Calibration curve . 3
7.2.2 Calculation of isotactic index II .
na 4
8 Method B — Absolute method . 4
8.1 Procedure . 4
8.1.1 Measurement of reference samples by n-heptane extraction . 4
8.1.2 LR­NMR measurement procedure of reference samples . 4
8.1.3 LR­NMR measurement procedure of test samples . 4
8.2 Calculation . 4
8.2.1 Calibration curve . 4
8.2.2 Calculation of isotactic index II .
nb 5
9 Expression of results . 5
10 Test report . 5
Annex A (informative) Example of a calibration curve for method A . 7
Annex B (informative) Example of a calibration curve for method B . 8
Bibliography . 9
© ISO 2020 – All rights reserved iii

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ISO/FDIS 24076:2020(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
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organizations, governmental and non­governmental, 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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 9,
Thermoplastic materials.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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ISO/FDIS 24076:2020(E)

Introduction
The LR­NMR method in this document is a relative method established with ISO 9113 as the absolute
method. The method and concept of isotactic index of polypropylene are specified in ISO 9113, that is,
the polypropylene sample is separated into the extractable and the unextractable matter by n-heptane
extraction, and the percentage of unextractable matter in the sample is calculated as isotactic index.
Isotactic index in ISO 9113 sounds similar to tacticity (isotacticity or stereotacticity) of polymer chain,
but the concept and result are different. The result is related to but not equal to the tacticity (isotacticity
or stereotacticity) of molecular chain, which can be determined by high resolution carbon-13 nuclear
magnetic resonance and infrared method. The result of ISO 9113 is also related to crystallization,
molecular weight, chain entanglement of the sample, solvent solubility and other effects.
For solid polymers, extraction always takes a long time for the diffusion of long molecular chain from
polymer to solvent. To improve test efficiency, relative methods are developed. This document provides
a relative non-destructive method for the determination of isotactic index by low-resolution nuclear
magnetic resonance spectrometry through a calibration curve establishing with magnetic signal and
isotactic index determined by ISO 9113. No solvent is used, and the determination efficiency is improved
during samples measurement procedure except for the calibration part.
© ISO 2020 – All rights reserved v

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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 24076:2020(E)
Plastics — Polypropylene (PP) — Determination of
isotactic index by low-resolution nuclear magnetic
resonance spectrometry
1 Scope
This document specifies a relative method for the determination of polypropylene (PP) isotactic index
by low-resolution pulsed nuclear magnetic resonance spectroscopy (LR-NMR).
This method provides for the identification and coding of types H propylene (PP-H) plastics according
to ISO 19069­1.
This method is suitable for base polymers and is not applicable for mixtures.
NOTE The direct method for the determination of polypropylene isotactic index is specified in ISO 9113.
2 Normative references
The following documents are referred to in the text in such a way that some or all of t
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