ISO INTERNATIONAL STANDARD 10398 First edition 1998-07-01 Rubber ldentification of accelerators in cured and uncured compounds Caoutchouc ldentification des accelerateurs dans les mélanges vulcanisés ou non [so Reference number ISO 10398:1998(E) ISO 10398:1998(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies (isO 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 10398 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products. @ISO1998 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. InternationalOrganizationforStandardization Casepostale56·CH-1211Geneve20·Switzerland Internet [email protected] X.400 C=ch; a=400net; p=iso; 0=isocs; S=central Printed in Switzerland ISO 10398:1998(E) INTERNATIONAL STANDARD @ISO Rubber ldentification of accelerators in cured and uncured compounds WARNING - Persons using this International Standard should be familiar with normal laboratory practice This standard does not purport to address all of the safety problems, if any, associated with its use. It is the with any national regulatory conditions. 1 Scope 1.1 This International Standard specifies methods using gas chromatography (GC) and thin layer chromatography (TLC) for the separation and identification of the following classes of accelerators in vulcanized and unvulcanized compounds: thiazoles sulfenamides thiurams and dithiocarbamates guanidines dithiodimorpholine 1.2 When 2-mercaptobenzothiazole (MBT) is identified and no sulfenamides are present, it is not possible to establish if the original accelerator was MBT and/or its salts or 2,2'-dibenzothiazoledisulfide (MBTS) as each of these accelerators may be produced from the others during the vulcanization process. 1.3 When sulfenamides are identified, it is not possible to establish if MBT and/or its salts and MBTS are present as these accelerators may be produced from 2-mercaptobenzothiazole sulfenamides during the vulcanization process. 1.4 The methods do not distinguish thiurams and dithiocarbamates derived from the same amines. benzothiazole (MBS) or dithiomorpholine as morpholine may be formed from MBS and dithiodimorpholine during the vulcanizationprocess. separation from vulcanized compounds is difficult due to the lesser ability of solvents to penetrate the vulcanized matrix. 1.7 Some compounding ingredients may interfere with method B. In such cases methods A or C shall be used. 2 Principle 2.1 Method A Identification of amines via GC and thiazoles via TLC 2.1.1 A portion of the sample compound is refluxed with hydrochloric acid (HCl) to hydrolyze sulfenamides, the amines are separated by GC as their trifluoroacetamide derivatives. ldentification may also be effected by comparison of GC retention times of sample and standard trifluoroacetamides, prepared and analyzed under the same analysis conditions.