1、BS ISO 9924-2:2016Rubber and rubber products Determination of thecomposition of vulcanizatesand uncured compounds bythermogravimetryPart 2: Acrylonitrile-butadiene andhalobutyl rubbersBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 9924-2:2016 BRITISH STANDARD
2、National forewordThis British Standard is the UK implementation of ISO 9924-2:2016. Itsupersedes BS ISO 9924-2:2000+A1:2012 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/22, Testing and analysis of rubber.A list of organizations represented on thi
3、s committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016. Published by BSI StandardsLimited 2016ISBN 978 0 580 92770 6ICS 83.
4、060Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 July 2016.Amendments issued since publicationDate Text affectedBS ISO 9924-2:2016 ISO 2016Rubber and rubber p
5、roducts Determination of the composition of vulcanizates and uncured compounds by thermogravimetry Part 2: Acrylonitrile-butadiene and halobutyl rubbersCaoutchouc et produits base de caoutchouc Dtermination de la composition des vulcanisats et mlanges non vulcaniss par thermogravimtrie Partie 2: Cao
6、utchoucs acrylonitrile-butadine et butyl halognINTERNATIONAL STANDARDISO9924-2Second edition2016-08-01Reference numberISO 9924-2:2016(E)BS ISO 9924-2:2016ISO 9924-2:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherw
7、ise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address be
8、low or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 9924-2:2016ISO 9924-2:2016(E)Foreword iv1 Scope . 12 Normative references 13 Principle
9、24 Reagents 25 Apparatus . 26 Thermogravimetric analyser checks . 37 Procedure. 48 Expression of results 59 Precision . 910 Test report . 9Annex A (informative) Precision 10 ISO 2016 All rights reserved iiiContents PageBS ISO 9924-2:2016ISO 9924-2:2016(E)ForewordISO (the International Organization f
10、or 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 th
11、e 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.The proce
12、dures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 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 editoria
13、l rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention 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. Details of any patent rights i
14、dentified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanati
15、on on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.The committee responsib
16、le for this document is ISO/TC 45, Rubber and rubber products, SC 2, Testing and analysis.This second edition cancels and replaces the first edition (ISO 9924-2:2000), of which it constitutes a minor revision. It also incorporates the amendment ISO 9924-2:2000/Amd 1:2012. The following changes have
17、been made: precision clause moved to Annex A.ISO 9924 consists of the following parts, under the general title Rubber and rubber products Determination of the composition of vulcanizates and uncured compounds by thermogravimetry: Part 1: Butadiene, ethylene-propylene copolymer and terpolymer, isobut
18、ene-isoprene, isoprene and styrene-butadiene rubbers Part 2: Acrylonitrile-butadiene and halobutyl rubbers Part 3: Hydrocarbon rubbers, halogenated rubbers and polysiloxane rubbers after extractioniv ISO 2016 All rights reservedBS ISO 9924-2:2016INTERNATIONAL STANDARD ISO 9924-2:2016(E)Rubber and ru
19、bber products Determination of the composition of vulcanizates and uncured compounds by thermogravimetry Part 2: Acrylonitrile-butadiene and halobutyl rubbersWARNING Persons using this part of ISO 9924 should be familiar with normal laboratory practice. This part of ISO 9924 does not purport to addr
20、ess 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 national regulatory conditions.1 Scope1.1 This part of ISO 9924 specifies a thermogravimetric method for the de
21、termination of the total organic content, carbon black content, carbonaceous residue and ash in vulcanizates and uncured compounds containing polymers which form a carbonaceous residue on pyrolysis (see 1.2). The loss in mass at around 300 C is an approximate guide to the volatile-matter content of
22、the compound.1.2 The method is suitable for the analysis of rubber compounds and vulcanizates containing the hydrocarbon polymers covered by ISO 9924-1 plus the following copolymers with polar groups which form a carbonaceous residue on pyrolysis:a) acrylonitrile-butadiene copolymers (NBRs);b) carbo
23、xylated acrylonitrile-butadiene copolymers (XNBRs);c) hydrogenated acrylonitrile-butadiene copolymers (HNBRs);d) chlorinated isobutylene-isoprene copolymers (CIIRs);e) brominated isobutylene-isoprene copolymers (BIIRs).NOTE 1 The field of application of the method may be extended to include the anal
24、ysis of compounds containing rubbers different from those given in this subclause, provided that the applicability of the method is tested beforehand using known compounds or vulcanizates having similar composition.NOTE 2 The method is not suitable for compounds containing mineral fillers, such as c
25、arbonates or hydrated aluminium oxides, which decompose in the temperature range from 25 C to 800 C, unless suitable corrections based on prior knowledge of filler behaviour can be made.NOTE 3 The method is not suitable for the determination of the total polymer content of compounds containing non-r
26、ubber organic ingredients that cannot be completely removed by solvent extraction carried out in accordance with ISO 1407.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, o
27、nly the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 1407, Rubber Determination of solvent extract ISO 2016 All rights reserved 1BS ISO 9924-2:2016ISO 9924-2:2016(E)3 Principle3.1 A weighed test portion is heated,
28、 following a pre-set programme, from 40 C to 600 C in a stream of nitrogen until all the organic material is pyrolysed. If nitrile-butadiene copolymers are present, a small amount of the polymer will be pyrolysed to form a carbonaceous residue that has to be determined in order to obtain the correct
29、 total organic content.3.2 For this purpose, the oven temperature is decreased to 400 C in a stream of nitrogen and maintained at 400 C for 5 min. The gas stream is then changed from nitrogen to air or oxygen and the oven temperature raised slowly to 800 C. During this heating in an oxidizing atmosp
30、here, two distinct losses in mass occur due to combustion. The first is due to the combustion of the carbonaceous residue, and the amount is determined and added to the previously determined loss in nitrogen at 600 C to obtain the correct value of the total organic content. The second is due to the
31、normal combustion of the carbon black.NOTE The total rubber content is calculated by subtracting the value of the solvent extract, determined in accordance with ISO 1407, from the total organic content, provided that all non-rubber ingredients can be extracted.3.3 The mass of the residue at 800 C re
32、presents the ash.4 Reagents4.1 Dry nitrogen, with an oxygen content of less than 10 mg/kg (ppm).4.2 Dry air or oxygen.5 Apparatus5.1 Thermogravimetric analyser.There are many types of analyser commercially available. All should be suitable for use with this part of ISO 9924, but their suitability sh
33、ould be checked using the procedure in Clause 6. Calibrate and operate the thermogravimetric analyser in accordance with the manufacturers instructions.The basic components of an analyser are as follows.5.1.1 Thermogravimetric balance.5.1.2 Electrically heated, thermo-regulated oven.5.1.3 Temperatur
34、e programmer, for the oven.5.1.4 Switching device, allowing either a stream of nitrogen or, alternatively, a stream of air or oxygen to flow through the oven at a predetermined and constant flow rate.5.1.5 X/Y recorder, for recording the temperature/mass plot. Alternatively, temperature/time and mas
35、s/time plots may be recorded simultaneously using a two-pen Y/T recorder. Digital data acquisition stations with related software for drawing the temperature/mass and/or time/mass curves are also suitable; in this case, better accuracy in the calculation of the mass losses can be achieved.5.1.6 Auxi
36、liary equipment for producing differential curves (mandatory for this part of ISO 9924).2 ISO 2016 All rights reservedBS ISO 9924-2:2016ISO 9924-2:2016(E)5.1.7 Analytical balance, capable of weighing to 0,1 mg.6 Thermogravimetric analyser checks6.1 Measurement of purge time, tp6.1.1 Place a test por
37、tion of carbon black or black-filled rubber, as specified in the manufacturers instructions, in the thermobalance sample pan and heat to 650 C in a stream of nitrogen, at the maximum rate allowed by the temperature programmer.6.1.2 Maintaining the temperature at 650 C, introduce air or oxygen and al
38、low the test portion to combust fully.6.1.3 When there is no further mass change, switch off the oven heater and allow the oven to cool to room temperature, maintaining the air or oxygen flow. At this point, the oven will have been thoroughly purged with air or oxygen. The following operations are d
39、esigned to determine the time, tp, required to completely restore the inert atmosphere of nitrogen.6.1.4 With the oven at 25 C 5 C, introduce a fresh test portion of carbon black, of mass as specified in the manufacturers instructions, into the balance pan and close the apparatus.6.1.5 Record the ti
40、me, t1, switch over to nitrogen gas flow, set the oven temperature to increase to 650 C at a rate of 10 C/min and then hold the temperature constant.6.1.6 Observe the thermogravimetric analyser mass trace and, when this no longer indicates a mass loss with time, note the time, t2.As a check, the pan
41、 should still contain carbon black since the mass loss should be constant if not all the carbon black has burned off during the heating time.6.1.7 The purge time, tp, which is the time required to purge all oxygen from the system, is given by Formula (1):tp= t2 t1(1)6.2 Discrimination between carbon
42、 black and calcium carbonate6.2.1 Calcium carbonate will decompose to calcium oxide when heated to 800 C. Carbon black is thermally stable up to this temperature in a nitrogen atmosphere. In air or oxygen, however, carbon black will be oxidized to carbon dioxide at 800 C.6.2.2 Provided that nitrogen
43、 having a low enough concentration of oxygen is used, that purging is carried out for a time greater than the purge time determined in 6.1, that there are no leaks in the apparatus, and that the oven design and gas flow rate ensure that all carbon dioxide is swept out from the sample chamber, there
44、should be no problem in distinguishing between, and measuring separately, black and whiting (calcium carbonate). To check the operation of the thermogravimetric analyser, carry out the following procedure.6.2.3 Grind together equal (to within 1 %) masses of analytical-grade calcium carbonate and the
45、 purest grade of carbon black available.6.2.4 Purge the apparatus with nitrogen for 10 min beyond the purge time, tp. ISO 2016 All rights reserved 3BS ISO 9924-2:2016ISO 9924-2:2016(E)6.2.5 Switch on the recorder and set the oven temperature to 25 C 5 C.6.2.6 Into the thermogravimetric analyser bala
46、nce pan, introduce a mass of the carbon black/calcium carbonate mixture (see 6.2.3) as specified in the manufacturers instructions.6.2.7 Close the apparatus and purge with a stream of nitrogen at a constant and predetermined flow rate which is in agreement with the manufacturers instructions. Contin
47、ue purging with nitrogen for a time which is greater than the purge time, tp(see 6.1).6.2.8 Raise the oven temperature to 800 C at a rate of 10 C/min.6.2.9 Maintain the oven temperature at 800 C until the mass indicated on the mass/temperature (or mass/time) plot is constant, then lower the temperat
48、ure to 300 C.6.2.10 Switch from the stream of nitrogen to a stream of air or oxygen. Adjust the total flow rate of the gas flowing through the apparatus so that there is no discernible change in the apparent mass of the sample. This procedure corrects for changes in buoyancy of the balance pan and t
49、est portion in gases of different density.6.2.11 Raise the oven temperature to 800 C as rapidly as possible and maintain it at this temperature for 15 min or until the mass indicated on the plot is constant.6.2.12 Switch off the oven heater and replace the stream of air or oxygen by a stream of pure nitrogen. Switch off the recorder and empty the ash residue from the balance pan. The apparatus is now ready for the next test portion.6.2.13 Determine the ratio, R, of the mass changes in the two differe
