ISO 3451-2:1998

Plastics - Determination of ash - Part 2: Poly(alkylene terephthalate) materials

This part of ISO 3451 specifies methods for determination of the ash of poly(ethylene terephthalate), poly(butylene terephthalate) and copolymers of the two, both filled and unfilled. The general procedures given in ISO 3451-1 are followed. For unfilled materials method A or method C of ISO 3451-1:1997 is used. For filled and glass-fibre reinforced materials method A of ISO 3451-1:1997 is used. For glass-fibre filled materials, containing flame retardant, antimony trioxide, and/or other, volatilize additives, for instance pigment zinc sulfide, a modification is incorporated to remove these as volatile bromine component(s).

Plastiques — Détermination du taux de cendres — Partie 2: Matières poly(téréphtalate d'alkylène)

La présente partie de l'ISO 3451 spécifie les méthodes de détermination du taux de cendres du polyéthylène téréphtalate, du polybutylène téréphtalate et des copolymères correspondants chargés et non chargés. Les modes opératoires généraux indiqués dans la norme ISO 3451-1 ont été suivis. Pour les matériaux non chargés, on utilise la méthode A ou la méthode C de l'ISO 3451-1:1997. Pour les matériaux chargés et ceux renforcés de fibres de verre, on suit la méthode A décrite dans l'ISO 3451-1:1997. Pour les matériaux chargés de fibres de verre et contenant un agent ignifugeant, du trioxyde d'antimoine et/ou d'autres additifs volatilisables tels que des pigments de sulfure de zinc, une modification a été apportée pour éliminer ces additifs sous forme de composant(s) volatil(s) du brome.

Polimerni materiali - Določevanje pepela - 2. del: Polialkilenteraftalatni materiali

General Information

• Status: Published
• Publication Date: 19-Dec-1998
• ICS: 83.080.20 - Thermoplastic materials
• Technical Committee: ISO/TC 61/SC 5 - Physical-chemical properties
• Drafting Committee: ISO/TC 61/SC 5/WG 11 - Analytical methods
• Current Stage: 9093 - International Standard confirmed
• Start Date: 15-Jun-2022
• Completion Date: 13-Dec-2025
• Ref Project: SIST ISO 3451-2:2000 - Plastics -- Determination of ash -- Part 2: Poly(alkylene terephthalate) materials

Relations

• Revised: SIST ISO 3451-2:1996 - Plastics -- Determination of ash -- Part 2: Polyalkylene terephthalates
• Effective Date: 12-May-2008
• Revises: ISO 3451-2:1984 - Plastics - Determination of ash - Part 2: Polyalkylene terephthalates
• Effective Date: 15-Apr-2008

Overview

ISO 3451-2:1998 specifies standardized methods for the determination of ash content in poly(alkylene terephthalate) materials, including poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), and their copolymers. This international standard is published by ISO and applies to both filled and unfilled plastics. It complements the general procedures outlined in ISO 3451-1 by adapting the approach specifically for poly(alkylene terephthalate) materials, ensuring accuracy and repeatability when analyzing ash content in thermoplastic polymers.

Ash content analysis is critical in evaluating the quality, composition, and performance characteristics of polymeric materials, especially when additives like glass fibres or flame retardants are involved. ISO 3451-2 provides detailed procedures for calcination and residue analysis, enabling manufacturers, laboratories, and quality control professionals to obtain reliable results.

Key Topics

• Scope and Material Types
  Covers unfilled and filled poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), and related copolymers. Both glass-fibre reinforced and flame-retarded compounds are included.

• Analytical Methods

  • Method A (direct calcination) and Method C (calcination after mineralization with sulfuric acid) as described in ISO 3451-1:1997.
  • Use of decabromobiphenyl (DBB) for modified ash determination in materials containing flame retardants like antimony trioxide and brominated additives.

• Sample Preparation and Apparatus
  Fragments, grains, or powders are dried and prepared with precise mass measurement to ensure consistency. Specified apparatus includes silica, porcelain, or platinum crucibles, and a muffle furnace with controlled temperatures between 600 °C - 850 °C.

• Calcination Procedures
  Different temperature regimens and sample treatments apply depending on filler type and presence of volatile additives. For glass fibre-reinforced materials with flame retardants, special handling with DBB minimizes inaccuracies due to volatile halogenated components.

• Result Expression
  Ash content is expressed as a mass percentage, calculated from the sample mass and the residual ash after combustion. Results are averaged and reported with an accuracy of 0.1%.

• Fidelity and Accuracy
  Repeatability and reproducibility data are provided, based on inter-laboratory studies of PET materials with common fillers like SiO2 and TiO2. The standard cautions on the need for further data on methods involving DBB and glass fibre reinforcement.

• Safety Notes
  Use of chemicals such as decabromobiphenyl and sulfuric acid requires adherence to strict safety protocols due to potential release of harmful compounds such as dioxins.

Applications

ISO 3451-2 is essential for:

• Quality control in plastics manufacturing: Accurate ash content determination helps verify filler and additive levels in poly(alkylene terephthalate) materials.
• Material certification: Ensures conformity to specifications for automotive, electronics, and industrial components made from PET, PBT, and copolymers.
• Research and development: Helps assess the effects of fillers, flame retardants, and processing conditions on the composition and performance of polymers.
• Regulatory compliance: Provides validated procedures supporting compliance with chemical and material standards globally.
• Failure analysis: Determines contaminant or filler concentrations during product testing or after field returns.

Related Standards

• ISO 3451-1:1997 – Plastics – Determination of ash – Part 1: General methods. Provides foundational procedures referenced throughout ISO 3451-2.
• ISO 3451-3 to ISO 3451-5 – Further parts covering ash determination for other plastics like cellulose acetate, polyamides, and PVC.
• Other ISO standards on plastics testing, such as ISO 527 (tensile properties) and ISO 1133 (melt flow rate), which complement ash content analysis in comprehensive polymer characterization.

---

By following ISO 3451-2:1998, stakeholders in the plastics industry can ensure consistent, validated, and internationally recognized methods for accurately determining ash contents in poly(alkylene terephthalate) materials-vital for product quality, safety, and performance assurance.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2000
3ROLPHUQLPDWHULDOL'RORþHYDQMHSHSHODGHO3ROLDONLOHQWHUDIWDODWQLPDWHULDOL
Plastics -- Determination of ash -- Part 2: Poly(alkylene terephthalate) materials
Plastiques -- Détermination du taux de cendres -- Partie 2: Matières poly(téréphtalate
d'alkylène)
Ta slovenski standard je istoveten z: ISO 3451-2:1998
ICS:
83.080.20 Plastomeri Thermoplastic materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 3451-2
Second edition
1998-12-15
Plastics — Determination of ash —
Part 2:
Poly(alkylene terephthalate) materials
Plastiques — Détermination du taux de cendres —
Partie 2: Matières poly(téréphtalate d'alkylène)
A
Reference number
Contents
1 Scope .1
2 Normative reference .1
3 Principle.1
3.1 Unfilled materials.1
3.2 Filled and glass-fibre reinforced materials .1
3.3 Flame-retardant materials reinforced with glass fibre.2
4 Reagents (method C or method A in the presence of DBB) .2
5 Apparatus .2
6 Procedure .2
6.1 Test portion .2
6.2 Unfilled materials.3
6.3 Filled and glass-fibre reinforced materials .3
6.4 Materials reinforced with glass fibre containing flame-retardant antimony trioxide and/or other
volatilizable additives.3
7 Expression of results .4
8 Precision.4
9 Test report .4
©  ISO 1998
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 [e-mail]
Printed in Switzerland
ii
© ISO
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 3451-2 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 3451-2:1984), which has been technically revised.
ISO 3451 consists of the following parts, under the general title Plastics — Determination of ash:
 Part 1: General methods
 Part 2: Poly(alkylene terephthalate) materials
 Part 3: Unplasticized cellulose acetate
 Part 4: Polyamides
 Part 5: Poly(vinyl chloride)
iii
INTERNATIONAL STANDARD  © ISO ISO 3451-2:1998(E)
Plastics — Determination of ash —
Part 2:
Poly(alkylene terephthalate) materials
WARNING — This part of ISO 3451 may involve hazardous chemicals, materials and operations. This part
of ISO 3451 does not purport to address the safety problems associated with its use. It is the responsibility
of the user to establish proper safety and health practices and determine the applicability of regulatory
limitations prior to use.
1 Scope
This part of ISO 3451 specifies methods for determination of the ash of poly(ethylene terephthalate), poly(butylene
terephthalate) and copolymers of the two, both filled and unfilled. The general procedures given in ISO 3451-1 are
followed. For unfilled materials method A or method C of ISO 3451-1:1997 is used. For filled and glass-fibre
reinforced materials method A of ISO 3451-1:1997 is used.
For glass-fibre filled materials, containing flame retardant, antimony trioxide, and/or other, volatilizable additives, for
instance pigment zinc sulfide, a modification is incorporated to remove these as volatile bromine component(s).
2 Normative reference
The following standard contains provisions which, through reference in this text, constitute provisions of this part of
ISO 3451. At the time of publication, the edition indicated was valid. All standards are subject to revision, and
parties to agreements based on this part of ISO 3451 are encouraged to investigate the possibility of applying the
most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid
International Standards.
ISO 3451-1:1997, Plastics — Determination of ash — Part 1: General methods.
3 Principle
3.1 Unfilled materials
Direct calcination by burning the organic matter and treating the residue at a high temperature until constant mass is
reached (ISO 3451-1:1997, method A).
If the material contains metal halides and/or metals (especially in the presence of halogenated material) which are
liable to evaporate during burning of the organic matter, calcination after sulfation can be applied (ISO 3451-1:1997,
method C). This procedure is carried out by heating the organic matter together with concentrated sulfuric acid up to
a temperature where fuming and subsequent burning of the organic matter occurs, and finally treating the residue at
a high temperature until constant mass is reached.
3.2 Filled and glass-fibre reinforced materials
Direct calcinat
...

INTERNATIONAL ISO
STANDARD 3451-2
Second edition
1998-12-15
Plastics — Determination of ash —
Part 2:
Poly(alkylene terephthalate) materials
Plastiques — Détermination du taux de cendres —
Partie 2: Matières poly(téréphtalate d'alkylène)
A
Reference number
Contents
1 Scope .1
2 Normative reference .1
3 Principle.1
3.1 Unfilled materials.1
3.2 Filled and glass-fibre reinforced materials .1
3.3 Flame-retardant materials reinforced with glass fibre.2
4 Reagents (method C or method A in the presence of DBB) .2
5 Apparatus .2
6 Procedure .2
6.1 Test portion .2
6.2 Unfilled materials.3
6.3 Filled and glass-fibre reinforced materials .3
6.4 Materials reinforced with glass fibre containing flame-retardant antimony trioxide and/or other
volatilizable additives.3
7 Expression of results .4
8 Precision.4
9 Test report .4
©  ISO 1998
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 [e-mail]
Printed in Switzerland
ii
© ISO
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 3451-2 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 3451-2:1984), which has been technically revised.
ISO 3451 consists of the following parts, under the general title Plastics — Determination of ash:
 Part 1: General methods
 Part 2: Poly(alkylene terephthalate) materials
 Part 3: Unplasticized cellulose acetate
 Part 4: Polyamides
 Part 5: Poly(vinyl chloride)
iii
INTERNATIONAL STANDARD  © ISO ISO 3451-2:1998(E)
Plastics — Determination of ash —
Part 2:
Poly(alkylene terephthalate) materials
WARNING — This part of ISO 3451 may involve hazardous chemicals, materials and operations. This part
of ISO 3451 does not purport to address the safety problems associated with its use. It is the responsibility
of the user to establish proper safety and health practices and determine the applicability of regulatory
limitations prior to use.
1 Scope
This part of ISO 3451 specifies methods for determination of the ash of poly(ethylene terephthalate), poly(butylene
terephthalate) and copolymers of the two, both filled and unfilled. The general procedures given in ISO 3451-1 are
followed. For unfilled materials method A or method C of ISO 3451-1:1997 is used. For filled and glass-fibre
reinforced materials method A of ISO 3451-1:1997 is used.
For glass-fibre filled materials, containing flame retardant, antimony trioxide, and/or other, volatilizable additives, for
instance pigment zinc sulfide, a modification is incorporated to remove these as volatile bromine component(s).
2 Normative reference
The following standard contains provisions which, through reference in this text, constitute provisions of this part of
ISO 3451. At the time of publication, the edition indicated was valid. All standards are subject to revision, and
parties to agreements based on this part of ISO 3451 are encouraged to investigate the possibility of applying the
most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid
International Standards.
ISO 3451-1:1997, Plastics — Determination of ash — Part 1: General methods.
3 Principle
3.1 Unfilled materials
Direct calcination by burning the organic matter and treating the residue at a high temperature until constant mass is
reached (ISO 3451-1:1997, method A).
If the material contains metal halides and/or metals (especially in the presence of halogenated material) which are
liable to evaporate during burning of the organic matter, calcination after sulfation can be applied (ISO 3451-1:1997,
method C). This procedure is carried out by heating the organic matter together with concentrated sulfuric acid up to
a temperature where fuming and subsequent burning of the organic matter occurs, and finally treating the residue at
a high temperature until constant mass is reached.
3.2 Filled and glass-fibre reinforced materials
Direct calcination, by burning the organic matter and treating the residue at a high temperature until constant mass
is reached (ISO 3451-1:1997, method A) (see note 1 in 3.3).
© ISO
3.3 Flame-retardant materials reinforced with glass fibre
Calcination by burning the organic matter in the presence of decabromobiphenyl (DBB) and finally treating the
residue at a high temperature until constant mass is reached (ISO 3451-1:1997, method A)
...

NORME ISO
INTERNATIONALE 3451-2
Deuxième édition
1998-12-15
Plastiques — Détermination
du taux de cendres —
Partie 2:
Matières poly(téréphtalate d'alkylène)
Plastics — Determination of ash —
Part 2: Poly(alkylene terephthalate) materials
A
Numéro de référence
Sommaire
1 Domaine d'application.1
2 Référence normative .1
3 Principe.1
3.1 Matériaux non chargés.1
3.2 Matériaux chargés et renforcés de fibres de verre.2
3.3 Matériaux ignifugés renforcés de fibres de verre.2
4 Réactifs (méthode C ou méthode A en présence de DBB) .2
5 Appareillage .2
6 Mode opératoire.2
6.1 Prise d'essai .3
6.2 Matériaux non chargés.3
6.3 Matériaux chargés et renforcés de fibres de verre.3
6.4 Matériaux renforcés de fibres de verre et contenant comme ignifugeant du trioxyde d’antimoine
et/ou d'autres additifs volatils .3
7 Expression des résultats .4
8 Fidélité .4
9 Rapport d'essai .5
©  ISO 1998
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publication ne peut être reproduite ni utilisée sous quelque
forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l'accord écrit de l'éditeur.
Organisation internationale de normalisation
Case postale 56 • CH-1211 Genève 20 • Suisse
Internet [e-mail]
Imprimé en Suisse
ii
© ISO
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux de
normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général confiée aux
comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du comité
technique créé à cet effet. Les organisations internationales, gouvernementales et non gouvernementales, en
liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec la Commission
électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les projets de Normes internationales adoptés par les comités techniques sont soumis aux comités membres pour
vote. Leur publication comme Normes internationales requiert l'approbation de 75 % au moins des comités
membres votants.
La Norme internationale ISO 3451-2 a été élaborée par le comité technique ISO/TC 61, Plastiques, sous-comité
SC 5, Propriétés physico-chimiques.
Cette deuxième édition annule et remplace la première édition (ISO 3451-2:1984), qui a fait l'objet d'une révision
technique.
L'ISO 3451 comprend les parties suivantes, présentées sous le titre général Plastiques — Détermination du taux de
cendres:
 Partie 1: Méthodes générales
 Partie 2: Matières poly(téréphtalate d'alkylène)
 Partie 3: Acétate de cellulose non plastifié
 Partie 4: Polyamides
 Partie 5: Poly(chlorure de vinyle)
iii
NORME INTERNATIONALE  © ISO ISO 3451-2:1998(F)
Plastiques — Détermination du taux de cendres —
Partie 2:
Matières poly(téréphtalate d'alkylène)
AVERTISSEMENT — La présente partie de l’ISO 3451 peut impliquer l'utilisation de produits chimiques et la
mise en œuvre de modes opératoires à caractère dangereux. Elle n’est pas censée aborder les problèmes
de sécurité liés à son utilisation. Il incombe à l'utilisateur d'établir, avant emploi, de bonnes pratiques
d'hygiène et de sécurité et de déterminer l'applicabilité des restrictions réglementaires.
1 Domaine d'application
La présente partie de l’ISO 3451 spécifie les méthodes de détermination du taux de cendres du polyéthylène
téréphtalate, du polybutylène téréphtalate et des copolymères correspondants chargés et non chargés. Les modes
opératoires généraux indiqués dans la norme ISO 3451-1 ont été suivis. Pour les matériaux non chargés, on utilise
la méthode A ou la méthode C de l'ISO 3451-1:1997. Pour les matériaux chargés et ceux renforcés de fibres de
verre, on suit la méthode A décrite dans l'ISO 3451-1:1997.
Pour les matériaux chargés de fibres de verre et contenant un agent ignifugeant, du trioxyde d'antimoine et/ou
d'autres additifs volatilisables tels que des pigments de sulfure de zinc, une modification a été apportée pour
éliminer ces additifs sous forme de composant(s) volatil(s) du brome.
2 Référence normative
La norme suivante contient des dispositions qui, par suite de la référence qui en est faite, constituent des
dispositions valables pour la présente partie de l’ISO 3451. Au moment de la publication, l’édition indiquée était en
vigueur. Toute norme est sujette à révision et les parties prenantes des accords fondés sur la présente partie de
l’ISO 3451 sont invitées à rechercher la possibilité d’appliquer l’édition la plus récente de la norme indiquée ci-
après. Les membres de la CEI et de l'ISO possèdent le registre des Normes internationales en vigueur à un
moment donné.
ISO 3451-1:1997, Plastiques — Détermination du taux de cendres — Partie 1: Méthodes générales.
3 Principe
3.1 Matériaux non chargés
Calcination directe par combustion de la matière organique et traitement du résidu à haute température jusqu'à
masse constante (ISO 3451-1:1997, méthode A).
Si le matériau contient des sels métalliques halogénés et/ou des métaux (spécialement en présence de matériaux
halogénés) qui soient susceptibles de s'évaporer durant la combustion de la matière organique, on peut procéder à
une calcination après minéralisation (ISO 3451-1:1997, méthode C). Ce mode opératoire consiste à chauffer la
matière organique en présence d'acide sulfurique concentré jusqu'à une température à laquelle il y a dégagement
de fumées et combustion de la matière organique, puis à traiter le résidu à haute température jusqu'à obtention
d'une masse constante.
© ISO
3.2 Matériaux chargés et renforcés de fibres de verre
Calcination directe par combustion de la matière organique et traitement du résidu à haute température jusqu'à
obtention d'une masse constante (ISO 3451-1:1997, méthode A) (voir la note 1 en 3.3).
3.3 Matériaux ignifugés renforcés de fibres de verre
Calcination par combustion de la matière organique en présence de décabromobiphényle (DBB) puis traitement du
résidu à haute température jusqu'à obtention d'une masse constante (ISO 3451-1:1997, méthode A).
NOTE 1 Certains additifs, comme par exemple le sulfure de zinc, sont eux aussi complètement volatilisés sous forme de
bromure par combustion de la matière organique en présence de décabromobiphényle (DBB). I
...