1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationRubber compounding ingredients Organic vulcanizing agents Determination of organic peroxide contentBS ISO 14932:2012National forewordThis British Standard is the UK implementatio
2、n of ISO 14932:2012.The UK participation in its preparation was entrusted to Technical CommitteePRI/23, Test methods for rubber and non-black compounding ingredients.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to
3、include all the necessary provisions of acontract. Users are responsible for its correct application. The British Standards Institution 2012Published by BSI Standards Limited 2012ISBN 978 0 580 69201 7ICS 83.040.20Compliance with a British Standard cannot confer immunity fromlegal obligations.This B
4、ritish Standard was published under the authority of the StandardsPolicy and Strategy Committee on 29 February 2012.Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS ISO 14932:2012Rubber compounding ingredients Organic vulcanizing agents Determination of organic peroxi
5、de contentIngrdients de mlange du caoutchouc Agents vulcanisants organiques Dtermination de la teneur en peroxyde organique ISO 2012Reference numberISO 14932:2012(E)First edition2012-01-15ISO14932INTERNATIONAL STANDARDBS ISO 14932:2012ISO 14932:2012(E)COPYRIGHT PROTECTED DOCUMENT ISO 2012All rights
6、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 either ISO at the address below or ISOs member body in the country of the re
7、quester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in Switzerlandii ISO 2012 All rights reservedBS ISO 14932:2012ISO 14932:2012(E) ISO 2012 All rights reserved iiiContents PageForeword iv1 Scope 11.1
8、 Titration method A for group a) peroxyketals 11.2 Titration method B for group b) diacyl peroxides 11.3 Titration method C for group c) diaralkyl and alkyl-aralkyl peroxides .11.4 Capillary gas-chromatography for dialkyl peroxides 12 Normative references .13 Terms and definitions .24 Titration meth
9、od A .24.1 Purpose 24.2 Principle .24.3 General procedure 34.4 Expression of results .35 Titration method B 45.1 Purpose 45.2 Principle .45.3 General procedure 55.4 Expression of results .56 Titration method C 66.1 Purpose 66.2 Principle .66.3 Reagents 66.4 Apparatus 76.5 Sample pre-treatment .76.6
10、Procedure 76.7 Expression of results .87 Determination of the assay of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane .97.1 Purpose 97.2 Principle .97.3 Reagents 97.4 Apparatus 97.5 Conditions .97.6 Procedure 107.7 Expression of results .118 Precision 119 Test report .11Annex A (informative) Method to
11、determine the content of peroxyketal .12Annex B (normative) Method to determine the content of tert-butyl hydroperoxide .16Annex C (informative) Method to determine the content of diacyl peroxides 20Annex D (normative) Sample preparation for the determination of peroxide in peroxide masterbatches .2
12、3Annex E (normative) Sample preparation for the determination of alkyl-aralkyl peroxide on polymers .26Annex F (informative) Precision .28Bibliography .33ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The w
13、ork 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-govern
14、mental, 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.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The m
15、ain task of technical committees is to prepare International Standards. 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.At
16、tention 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.ISO 14932 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 3,
17、Raw materials (including latex) for use in the rubber industry.ISO 14932:2012(E)iv ISO 2012 All rights reservedBS ISO 14932:2012INTERNATIONAL STANDARD ISO 14932:2012(E)Rubber compounding ingredients Organic vulcanizing agents Determination of organic peroxide contentWARNING Persons using this Intern
18、ational 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 responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any nati
19、onal regulatory conditions.1 ScopeThis International Standard specifies four methods for the determination of the content of the following groups of organic peroxides used as rubber vulcanizing agents. There are three titration methods and one using capillary gas-chromatography.1.1 Titration method
20、A for group a) peroxyketals DTBPC: 1,1-Di(tert-butylperoxy)cyclohexane; DBPMC: 1,1-Di(tert-butylperoxy)-2-methylcyclohexane; DBPTC: 1,1-Di(tert-butylperoxy)-3,3,5-trimethylcylcohexane; DBPB: 2,2-Di(tert-butylperoxy)butane; BPV: Butyl -4,4-di(tert-butylperoxy)valerate.1.2 Titration method B for group
21、 b) diacyl peroxides Dibenzoyl peroxide; Di(2,4-dichlorobenzoyl) peroxide; Di(4-methylbenzoyl) peroxide.1.3 Titration method C for group c) diaralkyl and alkyl-aralkyl peroxides Di(tert-butylperoxyisopropyl)benzene; Dicumyl peroxide; tert-Butyl cumyl peroxide.1.4 Capillary gas-chromatography for dia
22、lkyl peroxides 2,5-Dimethyl-2,5-di(tert-butylperoxy)hexane.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (inc
23、luding any amendments) applies.ISO 385, Laboratory glassware Burettes ISO 2012 All rights reserved 1BS ISO 14932:2012ISO 3696:1987, Water for analytical laboratory use Specification and test methodsISO 6353-1, Reagents for chemical analysis Part 1: General test methods3 Terms and definitionsFor the
24、purposes of this document, the following terms and definitions apply.3.1active oxygen of an organic peroxideoxygen-centered radicals, liberated by an organic peroxide, capable of initiating vulcanization of rubber compounds3.2peroxyketalperoxide obtained by the reaction of a ketone with tert-butyl h
25、ydroperoxide (TBHP) as shown in the following equation:22 2tert - tert -butyl OOH R C O R butyl OO CR R H O + +( ) ( ) ( )3.3diacyl peroxideperoxide obtained by the reaction of benzoyl chloride with hydrogen peroxide as shown in the following equation:2 26 5 2 2 6 5 6 5C H C O Cl H O C H C O OO C O
26、C H HCl + +( ) ( ) ( )3.4di-aralkyl peroxide alkyl-aralkyl peroxideperoxide obtained by the reaction of a benzyl alcohol with hydrogen peroxide in presence of sulfuric acid as shown in a simple case in the following equation:26 5 3 2 2 2 6 5 3 2 3 2 6 5 2C H C CH OH H O C H C CH OO CH C C H H O + +(
27、 ) ( ) ( )3.5dialkyl peroxideperoxide obtained by the reaction of a tert-butyl alcohol with hydrogen peroxide in presence of sulfuric acid as shown in the following equation:23 3 2 2 2 3 3 2 3 2 3 2CH C CH OH H O CH C CH OO CH C CH H O + +( ) ( ) ( )4 Titration method A4.1 PurposeThis test method sp
28、ecifies the procedure for the determination of the content of peroxyketals used as rubber organic vulcanizing agents and is applicable to DTBPC, DBPTC, DBPMC, DBPB and BPV.4.2 PrinciplePeroxyketales react with iodide in an acetic acid-hydrochloric acid medium, liberating an equivalent amount of iodi
29、ne which is titrated with a standard sodium thiosulfate solution:R OO R I H ROH ROH I + + + + +2 22ISO 14932:2012(E)2 ISO 2012 All rights reservedBS ISO 14932:2012I S O I S O2 2 324 622 2+ + Peroxyketals may contain traces of tert-butyl-hydro-peroxide (TBHP) as an impurity. The content of TBHP can b
30、e obtained by the method given in Annex B. The amount of active oxygen of the peroxyketal alone can then be obtained by subtraction, and the content of the peroxyketal is obtained by dividing the value by the theoretical amount of active oxygen.4.3 General procedureTwo procedures are shown as exampl
31、es depending upon the condition used for the peroxyketal oxidation-reduction reaction with potassium iodide (see methods A-1 and A-2 in Annex A).A weighed peroxyketal test sample (m1) is dissolved in an aqueous solution acidified with acetic acid and hydrochloric acid containing potassium iodide.Tit
32、rate the freed iodine with sodium thiosulfate of standard concentration and determine the volume required to complete the titration (V1).Repeat the same procedure without the peroxyketal as a blank test and determine the volume of sodium thiosulfate required to complete the titration (Vb1).Determine
33、 the content of TBHP in the sample (CHPO) (see Annex B).4.4 Expression of results4.4.1 Total amount of active oxygenCalculate the total amount of active oxygen, AO,kt, expressed as a percentage by mass to the nearest 0,1 %, by the following equation:AV V fmO,ktb= ( )0 000 81001 1 11,whereV1is the vo
34、lume, in cubic centimetres, of sodium thiosulfate solution used for the test;Vb1is the volume, in cubic centimetres, of sodium thiosulfate solution used for the blank test;f1is the factor of sodium thiosulfate solution, which is the ratio of the actual concentration to the theoretical concentration
35、(the normality is 0,1);m1is the mass, in grams, of the test sample;0,000 8 is the factor, in grams per cubic centimetre obtained as follows:0 000 815 999 420 111 000,= where15,999 4 is the atomic weight of oxygen;0,1 is the normality of the sodium thiosulfate solution.ISO 14932:2012(E) ISO 2012 All
36、rights reserved 3BS ISO 14932:20124.4.2 PurityCalculate the purity of the peroxyketal, Pktalone, expressed as a percentage by mass to the nearest 0,1 %, by the following equation:PA CAktO,kt HPOT,kt= 0177 5100,whereAO,ktis the total amount of active oxygen, in mass %;CHPOis the content of TBHP (see
37、Annex B), in mass %;0,177 5 is the value obtained by dividing the theoretical amount of active oxygen in tert-butyl hydroperoxide by 100;AT,ktis the theoretical amount of active oxygen of the peroxyketal, in mass %, obtained by the following equation:AnMT,kt1=15 999 41001,wheren1is the number of per
38、oxide bond in the peroxyketal;M1is the molecular mass of the peroxyketal (see Table 1).Table 1 Molecular mass of peroxyketalPeroxyketal n1M1AT,ktDTBPC 2 260,38 12,29DBPMC 2 274,40 11,66DBPTC 2 302,46 10,58DBPB 2 234,34 13,65BPV 2 334,46 9,575 Titration method B5.1 PurposeThis test method specifies t
39、he procedure for the determination of the content of diacyl peroxides such as dibenzoyl peroxide used as rubber organic vulcanizing agents.5.2 PrincipleDiacyl peroxides react with iodide in a solvent medium, liberating an equivalent amount of iodine which is titrated with a standard sodium thiosulfa
40、te solution:R OO R I H ROH ROH I + + + + +2 22ISO 14932:2012(E)4 ISO 2012 All rights reservedBS ISO 14932:2012I S O I S O2 2 324 622 2+ + The content of the diacyl peroxide is obtained by dividing the amount of active oxygen measured by the theoretical amount of active oxygen.5.3 General procedureTw
41、o procedures are shown as examples depending upon the solvent used for the diacyl peroxide oxidation-reduction reaction with potassium iodide (see methods B-1 and B-2 in Annex C).A weighed diacyl peroxide test sample (m2) is dissolved in dilute acetic acid containing potassium iodide.Titrate the fre
42、ed iodine with sodium thiosulfate of standard concentration and determine the volume required to complete the titration (V2).Repeat the same procedure without the diacyl peroxide as a blank test and determine the volume of sodium thiosulfate required to complete the titration (Vb2).5.4 Expression of
43、 resultsCalculate the purity of the diacyl peroxide, Pdaexpressed as a percentage mass fraction to the nearest 0,1 %, by the following equation:PV VfmAda2 bT,da= ( )0 000 8 100100222,whereV2is the volume, in cubic centimetres, of sodium thiosulfate solution used for the test;Vb2is the volume, in cub
44、ic centimetres, of sodium thiosulfate solution used for the blank test;f2is the factor of sodium thiosulfate solution, which is the ratio of the actual concentration to the theoretical concentration (the normality is 0,1);m2is the mass, in grams, of the test sample;AT,dais the theoretical amount of
45、active oxygen of the diacyl peroxide, in mass %, obtained by the following equation:AnMT,da2=15 999 41002,wheren2is the number of peroxide bond in the diacyl peroxide;M2is the molecular mass of the diacyl peroxide (see Table 2);0,000 8 is the factor, in grams per cubic centimetre, obtained by the fo
46、llowing equation:0 000 815 999 420 111000,= where15,999 4 is the atomic weight of oxygen;0,1 is the normality of the sodium thiosulfate solution.ISO 14932:2012(E) ISO 2012 All rights reserved 5BS ISO 14932:2012Table 2 Molecular mass of the diacyl peroxideDiacyl peroxide n2M2AT,daDibenzoyl peroxide 1
47、 242,23 6,61Di(2,4-dichlorobenzoyl) peroxide 1 380,01 4,21Di(4-methylbenzoyl) peroxide 1 270,29 5,926 Titration method C6.1 PurposeThis test method specifies the procedure to determine the content of alkyl-aralkyl peroxides such as dicumyl peroxide used as rubber organic vulcanizing agents.6.2 Princ
48、ipleThe alkyl aralkyl peroxide is refluxed in an inert atmosphere with acetic acid and a specified amount of water containing sodium iodide. Water is added to the reaction mixture to prevent side reactions taking place between iodide and decomposition products of the alkyl aralkyl peroxide.After ref
49、luxing for 30 min, the reaction mixture is cooled to room temperature to prevent side reactions between the liberated iodine and decomposition products of the alkyl aralkyl peroxide and to avoid loss of iodine through volatilization. After dilution with water, the liberated iodine is titrated with a standard sodium thiosulfate solution.This procedure gives a reproducible but not quant
