SN/T 3470.2-2013Rubber, raw. Determination of bound acrylonitrile content in acrylonitrile-butadiene rubber(NBR). Part 2: Kjeldahl method (English PDF)

Foreword

SN/T 3470 "raw rubber acrylonitrile - butadiene rubber (NBR) Determination of bound acrylonitrile content" is divided into two parts.

--- Part 1. combustion;

--- Part 2. Kjeldahl method.

This section SN/T 3470 Part 2.

This section drafted in accordance with GB/T 1.1-2009 given rules.

This section identical with the international standard ISO 24698-2:2008 (E).

This part uses ISO 24698-2. When 2008 (E) made editorial changes, the main differences are as follows.

--- With specified format GB/T 1.1-2009 of;

--- Punctuation by Chinese customs editor;

--- Use the decimal symbol instead of decimal symbol ",". ",";

--- With "this Part" instead of "this International Standard";

--- Delete international standards preface, directory and reports section.

This section proposed and managed by the National Certification and Accreditation Administration Committee.

1 Scope

SN/T 3470 specifies the portion of the automatic analyzer acrylonitrile - butadiene rubber (NBR) bound acrylonitrile content the method, which Kjeldahl method.

This section applies to automatic analyzer acrylonitrile - butadiene rubber (NBR) binding acrylonitrile content.

Note. Part 1 and Part 2 of this standard for any given rubber samples does not necessarily give the same result.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version suitable for use herein Member. For undated references, the latest edition (including any amendments) applies to this document.

GB/T 3516-2006 rubber solvent extraction of the analyte (ISO 1407:1992, MOD) GB/T 15340 natural, synthetic rubber raw sampling and sample preparation method (GB/T 15340-2008, ISO 1795:2000, IDT) Principle 3 Raw rubber sample digestion nitrogen is converted to ammonium in potassium sulfate, sulfuric acid and copper sulfate catalyst, broken down into after the addition of a strong base Ammonia, and then steam distilled and the boric acid solution is absorbed, the last titration solution titrated with standard acid.

4 Reagents and materials

Unless otherwise indicated, the reagents used were of analytical grade.

4.1 Standard substance. ammonium sulfate, purity >=99.5%.