BS ISO 9924-2-2016 Rubber and rubber products Determination of the composition of vulcanizates and uncured compounds by thermogravimetry Acrylonitrile-butadiene and halobu.pdf

1、BS ISO 9924-2:2016 Rubber and rubber products Determination of the composition of vulcanizates and uncured compounds by thermogravimetry Part 2: Acrylonitrile-butadiene and halobutyl rubbers BSI Standards Publication WB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 9924-2:2016 BRITISH

2、STANDARD National foreword This British Standard is the UK implementation of ISO 9924-2:2016. It supersedes BS ISO 9924-2:2000+A1:2012 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee PRI/22, Testing and analysis of rubber. A list of organizations repr

3、esented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2016. Published by BSI Standards Limited 2016 ISBN 978

4、0 580 92770 6 ICS 83.060 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2016. Amendments issued since publication Date Text affectedBS ISO 9924-2:2016

5、ISO 2016 Rubber and rubber products Determination of the composition of vulcanizates and uncured compounds by thermogravimetry Part 2: Acrylonitrile-butadiene and halobutyl rubbers Caoutchouc et produits base de caoutchouc Dtermination de la composition des vulcanisats et mlanges non vulcaniss par t

6、hermogravimtrie Partie 2: Caoutchoucs acrylonitrile-butadine et butyl halogn INTERNATIONAL STANDARD ISO 9924-2 Second edition 2016-08-01 Reference number ISO 9924-2:2016(E)BS ISO 9924-2:2016ISO 9924-2:2016(E)ii ISO 2016 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in Switzerl

7、and All rights reserved. Unless otherwise 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 reque

8、sted from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.orgBS ISO 9924-2:2016ISO 9924-2:2016(E)Foreword iv 1

9、 Scope . 1 2 Normative references 1 3 Principle 2 4 Reagents 2 5 Apparatus . 2 6 Thermogravimetric analyser checks . 3 7 Procedure. 4 8 Expression of results 5 9 Precision . 9 10 Test report . 9 Annex A (informative) Precision 10 ISO 2016 All rights reserved iii Contents PageBS ISO 9924-2:2016ISO 99

10、24-2:2016(E) Foreword ISO (the International Organization for 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

11、for which a technical committee has been established has the 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) o

12、n all matters of electrotechnical standardization. The procedures 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 note

13、d. This document was drafted in accordance with the editorial 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

14、any or all such patent rights. Details of any patent rights identified 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

15、 users and does not constitute an endorsement. For an explanation on the meaning of ISO specific terms and expressions related to conformit y assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the foll

16、owing URL: www.iso.org/iso/foreword.html. The committee responsible 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 th

17、e amendment ISO 9924-2:2000/Amd 1:2012. The following changes have 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: Pa

18、rt 1: Butadiene, ethylene-propylene copolymer and terpolymer, isobutene-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 I

19、SO 9924-2:2016INTERNATIONAL ST ANDARD ISO 9924-2:2016(E) Rubber and rubber products Determination of the composition of vulcanizates and uncured compounds by thermogravimetry Part 2: Acrylonitrile-butadiene and halobutyl rubbers WARNING Persons using this part of ISO 9924 should be familiar with nor

20、mal laboratory practice. This part of ISO 9924 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 national regulatory conditions. 1 Scope

21、1.1 This part of ISO 9924 specifies a thermogravimetric method for the determination 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 a

22、t around 300 C is an approximate guide to the volatile-matter content of 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

23、residue on pyrolysis: a) acrylonitrile-butadiene copolymers (NBRs); b) carboxylated acrylonitrile-butadiene copolymers (XNBRs); c) hydrogenated acrylonitrile-butadiene copolymers (HNBRs); d) chlorinated isobutylene-isoprene copolymers (CIIRs); e) brominated isobutylene-isoprene copolymers (BIIRs). N

24、OTE 1 The field of application of the method may be extended to include the analysis 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

25、 2 The method is not suitable for compounds containing mineral fillers, such as carbonates 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 suitabl

26、e for the determination of the total polymer content of compounds containing non-rubber organic ingredients that cannot be completely removed by solvent extraction carried out in accordance with ISO 1407. 2 Normative references The following documents, in whole or in part, are normatively referenced

27、 in this document and are indispensable for its application. For dated references, only 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

28、1BS ISO 9924-2:2016ISO 9924-2:2016(E) 3 Principle 3.1 A weighed test portion is heated, 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

29、to form a carbonaceous residue that has to be determined in order to obtain the correct 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

30、 the oven temperature raised slowly to 800 C. During this heating in an oxidizing atmosphere, 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 6

31、00 C to obtain the correct value of the total organic content. The second is due to the 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

32、 that all non-rubber ingredients can be extracted. 3.3 The mass of the residue at 800 C represents the ash. 4 Reagents 4.1 Dry nitrogen, with an oxygen content of less than 10 mg/kg (ppm). 4.2 Dry air or oxygen. 5 Apparatus 5.1 Thermogravimetric analyser. There are many types of analyser commerciall

33、y available. All should be suitable for use with this part of ISO 9924, but their suitability should 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.

34、 5.1.1 Thermogravimetric balance. 5.1.2 Electrically heated, thermo-regulated oven. 5.1.3 Temperature 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

35、. 5.1.5 X/Y recorder, for recording the temperature/mass plot. Alternatively, temperature/time and mass/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 su

36、itable; in this case, better accuracy in the calculation of the mass losses can be achieved. 5.1.6 Auxiliary 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 weigh

37、ing to 0,1 mg. 6 Thermogravimetric analyser checks 6.1 Measurement of purge time, t p 6.1.1 Place a test portion 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 allo

38、wed by the temperature programmer. 6.1.2 Maintaining the temperature at 650 C, introduce air or oxygen and allow 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 flo

39、w. At this point, the oven will have been thoroughly purged with air or oxygen. The following operations are designed to determine the time, t p , 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

40、 as specified in the manufacturers instructions, into the balance pan and close the apparatus. 6.1.5 Record the time, t 1 , 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 thermogravimetri

41、c analyser mass trace and, when this no longer indicates a mass loss with time, note the time, t 2 . As a check, the pan 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, t p , which is t

42、he time required to purge all oxygen from the system, is given by Formula (1): t p= t 2 t 1(1) 6.2 Discrimination between carbon black and calcium carbonate 6.2.1 Calcium carbonate will decompose to calcium oxide when heated to 800 C. Carbon black is thermally stable up to this temperature in a nitr

43、ogen atmosphere. In air or oxygen, however, carbon black will be oxidized to carbon dioxide at 800 C. 6.2.2 Provided that nitrogen 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

44、 apparatus, and that the oven design and gas flow rate ensure that all carbon dioxide is swept out from the sample chamber, there should be no problem in distinguishing between, and measuring separately, black and whiting (calcium carbonate). To check the operation of the thermogravimetric analyser,

45、 carry out the following procedure. 6.2.3 Grind together equal (to within 1 %) masses of analytical-grade calcium carbonate and the purest grade of carbon black available. 6.2.4 Purge the apparatus with nitrogen for 10 min beyond the purge time, t p . ISO 2016 All rights reserved 3BS ISO 9924-2:2016

46、ISO 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 balance 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 pu

47、rge with a stream of nitrogen at a constant and predetermined flow rate which is in agreement with the manufacturers instructions. Continue purging with nitrogen for a time which is greater than the purge time, t p(see 6.1). 6.2.8 Raise the oven temperature to 800 C at a rate of 10 C/min. 6.2.9 Main

48、tain the oven temperature at 800 C until the mass indicated on the mass/temperature (or mass/time) plot is constant, then lower the temperature 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 tha

49、t there is no discernible change in the apparent mass of the sample. This procedure corrects for changes in buoyancy of the balance pan and test 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 as