ISO 7725:2020 ゴムおよびゴム製品—塩素および臭素含有量の測定 | ページ 2

Foreword

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The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, 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, 2 (see www.iso.org/directives ).

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The committee responsible for this document is ISO/TC 45, Rubber and rubber products, Subcommittee SC 2, Testing and analysis.

This second edition cancels and replaces the first edition (ISO 7725:1991), which has been technically revised. The main changes compared to the previous edition are as follows:

• the ion chromatography method has been added in Clause 6;
• the titration procedure has been improved in Clause 7;
• the tubular furnace combustion method for sample preparation has been added in Annex A;
• the oxygen combustion flask method for sample preparation has been improved in Annex B;
• the oxygen combustion bomb method for sample preparation has been added in Annex C;
• mercury nitrate and hydrazine are no longer used due to their hazardous properties.

Introduction

The two test methods in this document for quantitative analysis can be used for any type of rubbers (i.e. raw rubber, vulcanized rubber or unvulcanized rubber) containing chlorine and/or bromine in any form of existence, such as an element of polymer chain, chemical additives or a part of contaminations.

Three combustion methods are given for preparation of sample solution, i.e. tubular furnace combustion method, oxygen combustion flask method and oxygen combustion bomb method. After sample solutions are prepared, a content determination procedure, i.e. either ion chromatography or potentiometric titration, follows. The most convenient and efficient method from the testing time and safeness points of view, is the combination of tubular furnace combustion and ion chromatography, as ion chromatography is widely used in quality control of polymer/rubber products or in environmental analysis.

1 Scope

This document specifies methods for the determination of chlorine and/or bromine present in raw rubber as well as vulcanized or unvulcanized rubber compounds.

The methods are applicable to natural rubbers and to the following synthetic rubbers: isoprene, styrene-butadiene, butadiene, butyl, halogenated butyl, nitrile, ethylene-propylene, chloroprene and epichlorohydrin.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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.

3 Terms and definitions

No terms and definitions are listed in this document.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

Bibliography