1、Rubber, raw Determination of the glass transition temperature by differential scanning calorimetry (DSC)BS ISO 22768:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06 ISO 2017Rubber, raw Determination of the glass transition temperature by differential scanning ca
2、lorimetry (DSC)Caoutchouc brut Dtermination de la temprature de transition vitreuse par analyse calorimtrique diffrentielle (DSC)INTERNATIONAL STANDARDISO22768Second edition2017-08Reference numberISO 22768:2017(E)National forewordThis British Standard is the UK implementation of ISO 22768:2017. It s
3、upersedes BS ISO 22768:2006, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee PRI/50, Raw materials (including latex) for use in the rubber industry.A list of organizations represented on this committee can be obtained on request to its secretary.This p
4、ublication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 94686 8ICS 83.060; 83.040.10Compliance with a British Standard cannot con
5、fer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2017.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS ISO 22768:2017 ISO 2017Rubber, raw Determination of the
6、glass transition temperature by differential scanning calorimetry (DSC)Caoutchouc brut Dtermination de la temprature de transition vitreuse par analyse calorimtrique diffrentielle (DSC)INTERNATIONAL STANDARDISO22768Second edition2017-08Reference numberISO 22768:2017(E)BS ISO 22768:2017ISO 22768:2017
7、(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll 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 post
8、ing on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below 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
9、 749 09 47copyrightiso.orgwww.iso.orgBS ISO 22768:2017ISO 22768:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by
10、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 below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 40
11、1CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgISO 22768:2017(E)Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Apparatus and materials 26 Test specimen 27 Conditioning 28 Calibration 29 Procedure. 29.1
12、 Gas flow rate 29.2 Loading the test specimen 29.3 Temperature scan . 310 Expression of results 311 Test report . 412 Precision . 5Annex A (informative) Precision . 6Bibliography 9 ISO 2017 All rights reserved iiiContents PageBS ISO 22768:2017ISO 22768:2017(E)ForewordISO (the International Organizat
13、ion 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 for which a technical committee has been established h
14、as 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) on all matters of electrotechnical standardization.The
15、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 noted. This document was drafted in accordance with the edi
16、torial 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
17、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 users and does not constitute an endorsement.For a
18、n explanation on the voluntary nature of standards, 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 .is
19、o .org/ iso/ foreword .html.This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 3, Raw materials (including latex) for use in the rubber industry.This second edition cancels and replaces the first edition (ISO 22768:2006), which has been technical
20、ly revised with the following changes: additional description on placing an empty pan (crucible) as reference; general DSC thermogram inserted to show an inflection point which should be Tg; move of the content of the clause on precision data to an informative Annex A.iv ISO 2017 All rights reserved
21、BS ISO 22768:2017ISO 22768:2017(E)ForewordISO (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 inte
22、rested 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-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnica
23、l Commission (IEC) on 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 docum
24、ents should be noted. 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 respons
25、ible for identifying 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
26、 for the convenience of users and does not constitute an endorsement.For an explanation on the voluntary nature of standards, 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) principl
27、es in the Technical Barriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 3, Raw materials (including latex) for use in the rubber industry.This second edition cancels
28、 and replaces the first edition (ISO 22768:2006), which has been technically revised with the following changes: additional description on placing an empty pan (crucible) as reference; general DSC thermogram inserted to show an inflection point which should be Tg; move of the content of the clause o
29、n precision data to an informative Annex A.iv ISO 2017 All rights reserved INTERNATIONAL STANDARD ISO 22768:2017(E)Rubber, raw Determination of the glass transition temperature by differential scanning calorimetry (DSC)WARNING Persons using this document should be familiar with normal laboratory pra
30、ctice. This document 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 ScopeThis document specifies a me
31、thod using a differential scanning calorimeter to determine the glass transition temperature of raw rubber.2 Normative referencesThe following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only t
32、he edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 1407, Rubber Determination of solvent extractISO 11357-1:2016, Plastics Differential scanning calorimetry (DSC) Part 1: General principlesISO 23529, Rubber General p
33、rocedures for preparing and conditioning test pieces for physical test methods3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 11357-1 and the following apply.ISO and IEC maintain terminological databases for use in standardization at the following add
34、resses: IEC Electropedia: available at h t t p :/ www .electropedia .org/ ISO Online browsing platform: available at h t t p :/ www .iso .org/ obp3.1glass transitionreversible change in an amorphous polymer, or in amorphous regions of a partially crystalline polymer, from (or to) a rubbery or viscou
35、s condition to (or from) a glassy or hard condition3.2glass transition temperatureTgapproximate midpoint of the temperature range over which the glass transition (3.1) takes placeNote 1 to entry: For the purposes of this document, the glass transition temperature is defined as the point of inflectio
36、n of the DSC curve which has been obtained at a heating rate of 20 C/min (see A.3).4 PrincipleThe change in specific heat capacity of the rubber as a function of temperature under a specified inert atmosphere is measured using a differential scanning calorimeter (DSC). The glass transition temperatu
37、re is determined from the curve thus produced. ISO 2017 All rights reserved 1BS ISO 22768:2017ISO 22768:2017(E)5 Apparatus and materials5.1 Differential scanning calorimeter, in accordance with ISO 11357-1:2016, 5.1.The calorimeter should be operated in a room held at standard laboratory temperature
38、. It should be protected from draughts, direct sunlight and sudden temperature changes.5.2 Specimen pans (crucibles), in accordance with ISO 11357-1:2016, 5.2.5.3 Gas supply, analytical grade, usually nitrogen or helium.5.4 Balance, capable of measuring the specimen mass to an accuracy of 0,000 1 g.
39、6 Test specimenThe test specimen shall be as representative as possible of the sample being examined and shall have a mass between 0,01 g and 0,02 g.To determine Tgof polymers, extract raw rubber in accordance with ISO 1407.7 ConditioningCondition the sample to be examined and the test specimen in a
40、ccordance with ISO 23529.8 CalibrationCalibrate the calorimeter according to the manufacturers instructions.The use of suitable analytical grade substances is recommended to check the accuracy of the temperature scale. Ideally, substances whose melting points bracket the temperature range of interes
41、t should be chosen. n-Octane, n-heptane and cyclohexane have been found to be useful. Indium should be used if a higher temperature calibrant is required.9 Procedure9.1 Gas flow rateThe same inert gas flow rate with a tolerance of 10 %, shall be used throughout the procedure. Flow rates between 10 m
42、l/min and 100 ml/min have been found to be suitable.9.2 Loading the test specimenDetermine the mass of the test specimen to an accuracy of 0,001 g. The same nominal mass shall be used for all determinations. If possible, the specimen shall have a flat surface so as to give good thermal contact with
43、the bottom of the pan.NOTE 1 Intimate thermal contact between the test specimen and the bottom of the pan is essential for good repeatability.Place the specimen in the pan, using tweezers and seal with a lid. Place the sealed pan in the calorimeter using tweezers.Do not handle the test specimen or t
44、he pan with bare hands.NOTE 2 Placing an empty pan with a lid as a reference helps to obtain stable DSC thermograms.2 ISO 2017 All rights reservedBS ISO 22768:2017ISO 22768:2017(E)5 Apparatus and materials5.1 Differential scanning calorimeter, in accordance with ISO 11357-1:2016, 5.1.The calorimeter
45、 should be operated in a room held at standard laboratory temperature. It should be protected from draughts, direct sunlight and sudden temperature changes.5.2 Specimen pans (crucibles), in accordance with ISO 11357-1:2016, 5.2.5.3 Gas supply, analytical grade, usually nitrogen or helium.5.4 Balance
46、, capable of measuring the specimen mass to an accuracy of 0,000 1 g.6 Test specimenThe test specimen shall be as representative as possible of the sample being examined and shall have a mass between 0,01 g and 0,02 g.To determine Tgof polymers, extract raw rubber in accordance with ISO 1407.7 Condi
47、tioningCondition the sample to be examined and the test specimen in accordance with ISO 23529.8 CalibrationCalibrate the calorimeter according to the manufacturers instructions.The use of suitable analytical grade substances is recommended to check the accuracy of the temperature scale. Ideally, sub
48、stances whose melting points bracket the temperature range of interest should be chosen. n-Octane, n-heptane and cyclohexane have been found to be useful. Indium should be used if a higher temperature calibrant is required.9 Procedure9.1 Gas flow rateThe same inert gas flow rate with a tolerance of
49、10 %, shall be used throughout the procedure. Flow rates between 10 ml/min and 100 ml/min have been found to be suitable.9.2 Loading the test specimenDetermine the mass of the test specimen to an accuracy of 0,001 g. The same nominal mass shall be used for all determinations. If possible, the specimen shall have a flat surface so as to give good thermal contact with the bottom of the pan.NOTE 1 Intimate thermal contact between the test specimen and the bottom of the pan is essential for good repeatabil
