1、Electrical insulating materials Thermal endurance propertiesPart 7-2: Results of the round robin tests to validate procedures of IEC TS 60216-7-1 by non-isothermal kinetic analysis of thermogravimetric dataPD IEC/TR 60216-7-2:2016BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05
2、/2013 15:06National forewordThis Published Document is the UK implementation of IEC/TR60216-7-2:2016.The UK participation in its preparation was entrusted to TechnicalCommittee GEL/112, Evaluation and qualification of electrical insulatingmaterials and systems.A list of organizations represented on
3、this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 92883 3ICS
4、 19.020; 29.020; 29.035.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This Published Document was published under the authority of theStandards Policy and Strategy Committee on 30 September 2016.Amendments/corrigenda issued since publicationDate Text affectedPUBLI
5、SHED DOCUMENTPD IEC/TR 60216-7-2:2016IEC TR 60216-7-2 Edition 1.0 2016-08 TECHNICAL REPORT Electrical insulating materials Thermal endurance properties Part 7-2: Results of the round robin tests to validate procedures of IEC TS 60216-7-1 by non-isothermal kinetic analysis of thermogravimetric data I
6、NTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 19.020; 29.020; 29.035.01 ISBN 978-2-8322-3606-2 Registered trademark of the International Electrotechnical Commission Warning! Make sure that you obtained this publication from an authorized distributor. colourinsidePD IEC/TR 60216-7-2:2016 2 IEC TR 6021
7、6-7-2:2016 IEC 2016 CONTENTS FOREWORD . 4 INTRODUCTION . 6 1 Scope 7 2 Normative references. 7 3 Terms and definitions 7 4 Test specimens . 8 5 Test apparatus 9 5.1 Thermogravimetric analyser (TGA) 9 5.2 Purge gas supplied into the TGA furnace . 9 6 Test procedures 9 6.1 General . 9 6.2 Precondition
8、ing of test samples . 10 6.3 TGA tests with multiple heating rates . 10 6.4 Calculation of the activation energy (Ea) 10 6.5 Determination of thermal endurance using TGA . 11 6.5.1 General . 11 6.5.2 Determination of RTEAby given degree of conversion from reference material (Method A) . 11 6.5.3 Det
9、ermination of TIAby fixed degree of conversion at 0,05 (Method B) . 12 7 Round robin test results . 12 7.1 TGA test results 12 7.2 Degree of conversion correlated to the activation energy from conventional heat ageing data . 12 7.3 HICAdetermined by Method A and Method B 13 7.4 RTEA determined by Me
10、thod A and TIAby Method B . 14 7.5 Difference between RTEAand TI determined by the conventional heat ageing tests 16 8 Observations from the round robin test results 17 8.1 General . 17 8.2 Sample weight variation 18 8.3 Humidity and hydrolysis of the sample . 19 8.4 Consideration on repeatability o
11、f TGA curves. 20 8.5 Baseline drift and responsiveness to heating rates of TGA . 21 9 Conclusion and recommendation . 24 Bibliography . 26 Figure 1 Fitting curve of plots between degree of conversion and activation energy determined by ISO 11358-2 (example) 11 Figure 2 Correlation between the initia
12、l sample mass of sample A and the difference of RTEA(TIA) from TI . 19 Figure 3 Correlation between the initial sample mass of sample B and the difference of RTEA(TIA) from TI . 19 Figure 4 Overlay charts of TGA curves in multiple heating rates in multiple laboratories (enlarged) 22 Figure 5 Logarit
13、hm plots for activation energy calculation . 23 Figure 6 Fitting curves of degree of conversion vs. activation energy by TGA 24 PD IEC/TR 60216-7-2:2016IEC TR 60216-7-2:2016 IEC 2016 3 Table 1 Heat ageing properties of the test specimens by the conventional procedure described in IEC 60216-5 9 Table
14、 2 Degree of conversion identical to the activation energy of the conventional heat ageing 13 Table 3 HICAdetermined by Method A and Method B for dielectric strength 13 Table 4 HICAdetermined by Method A and Method B for tensile strength . 14 Table 5 HICAdetermined by Method A and Method B for impac
15、t strength . 14 Table 6 RTEAdetermined by Method A and TIAby Method B for dielectric strength 15 Table 7 RTEAdetermined by Method A and TIAby Method B for tensile strength 15 Table 8 RTEAdetermined by Method A and TIAby Method B for impact strength 16 Table 9 Difference between RTEAor TIA, and TI fo
16、r dielectric strength . 16 Table 10 Difference between RTEAor TIA, and TI for tensile strength 17 Table 11 Difference between RTEAor TIA, and TI for impact strength 17 Table 12 Comparison of degree of conversion with original or rerun data at 8 K/min 21 PD IEC/TR 60216-7-2:2016 4 IEC TR 60216-7-2:20
17、16 IEC 2016 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ ELECTRICAL INSULATING MATERIALS THERMAL ENDURANCE PROPERTIES Part 7-2: Results of the round robin tests to validate procedures of IEC TS 60216-7-1 by non-isothermal kinetic analysis of thermogravimetric data FOREWORD 1) The International Electr
18、otechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. T
19、o this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC Nati
20、onal Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (I
21、SO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation
22、from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be
23、 held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. An
24、y divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access t
25、o IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individu
26、al experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, thi
27、s IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of thi
28、s IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. The main task of IEC technical committees is to prepare International Standards. However, a technical committee may propose the publication of a Technical Report wh
29、en it has collected data of a different kind from that which is normally published as an International Standard, for example “state of the art“. IEC TR 60216-2-7, which is a Technical Report, has been prepared by IEC technical committee 112: Evaluation and qualification of electrical insulating mate
30、rials and systems. PD IEC/TR 60216-7-2:2016IEC TR 60216-7-2:2016 IEC 2016 5 The text of this Technical Report is based on the following documents: Enquiry draft Report on voting 112/354/DTR 112/370/RVC Full information on the voting for the approval of this Technical Report can be found in the repor
31、t on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all parts in the IEC 60216 series, published under the general title Electrical insulating materials Thermal endurance properties, can be found on the IEC website.
32、 The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed, withdrawn, replaced by a revi
33、sed edition, or amended. A bilingual version of this publication may be issued at a later date. IMPORTANT The colour inside logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users should ther
34、efore print this document using a colour printer. PD IEC/TR 60216-7-2:2016 6 IEC TR 60216-7-2:2016 IEC 2016 INTRODUCTION IEC technical committee 112, (IEC/TC112) has been working on the development of IEC TS 60216-7-1 that considers the use of activation energy determined through thermal analytical
35、tools plus abbreviated conventional heat ageing to determine a thermal index on a polymeric compound. At the same time, the UL LTTA Forum has been discussing alternative methods that could speed up the determination of a thermal index. Members of the IEC/TC112 and of the UL LTTA Forum have joined ef
36、forts to determine whether the Technical Specification developed by IEC/TC112 can be used to offer an alternative method of evaluating polymeric compounds for a thermal index. Members of IEC/TC112 and the UL LTTA Forum decided to conduct a round robin test (RRT) using thermogravimetric analysis (TGA
37、) according to ISO 11358-2 on a known compound, with a known activation energy determined through conventional ageing with a view to validate the acceptability of IEC TS 60216-7-1, and to determine whether a similar thermal index could be calculated. The round robin testing was conducted with conven
38、tional TGA by multiple heating rates. However, running isothermal tests can be a follow up of this RRT. PD IEC/TR 60216-7-2:2016IEC TR 60216-7-2:2016 IEC 2016 7 ELECTRICAL INSULATING MATERIALS THERMAL ENDURANCE PROPERTIES Part 7-2: Results of the round robin tests to validate procedures of IEC TS 60
39、216-7-1 by non-isothermal kinetic analysis of thermogravimetric data 1 Scope The purpose of this part of IEC 60216, which is a Technical Report, is to validate the procedures of IEC TS 60216-7-1 in providing a similar temperature index to conventional methods used in other parts of the IEC 60216 ser
40、ies. These round robin test results do not provide statistical analysis for precisions. The round robin test focuses on preliminary studies to understand the evaluation and calculation procedures, influence on apparatus, and data variance among laboratories before determination of precisions. 2 Norm
41、ative references There are no normative references in this document. 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 activation energy Arrhenius activation energy Eaempirical parameter characterizing the exponential temperature dependence of
42、the reaction rate constant SOURCE: IUPAC “Goldbook” 3.2 end-point limit for a diagnostic property value based on which the thermal endurance is evaluated 3.3 time to end-point failure time time to reach the end point or conventional failure 3.4 relative temperature endurance index RTE numerical valu
43、e of the temperature in degrees Celsius at which the estimated time to end-point of the candidate material is the same as the estimated time to end-point of the reference material at a temperature equal to its assessed temperature index Note 1 to entry: RTEAis the relative temperature endurance inde
44、x calculated through the analytical procedure. PD IEC/TR 60216-7-2:2016 8 IEC TR 60216-7-2:2016 IEC 2016 3.5 temperature endurance index TI numerical value of the temperature in degrees Celsius derived from the thermal endurance relationship at a time of 20 000 h (or other specified time) Note 1 to
45、entry: TIAis the temperature index calculated through the analytical procedure. SOURCE: IEC 60050-212:2010, 212-12-11, modified the two notes have been deleted and replaced by a new note. 3.6 halving interval HIC numerical value of the temperature interval in kelvin which expresses the halving of th
46、e time to end-point taken at the temperature equal to TI Note 1 to entry: HICAis the halving interval calculated through the analytical procedure. 3.7 degree of conversion quantity of products present at a particular time and temperature during a reaction compared with the final quantity of the prod
47、ucts SOURCE: ISO 11358-2:2014, 3.3, modified the notes have been deleted 4 Test specimens For the round robin study, one generic type of polymer, liquid crystal polyester (LCP), was pre-selected as the round robin study which assumes one single thermal degradation reaction is predominant and directl
48、y correlated to the end-point of dielectric strength as a diagnostic property. LCP originally has very little entwining of molecules which exhibits crystalline properties as a liquid and therefore, there is less thermal transformation between solid and liquid, or between oven ageing conditions of co
49、nventional thermal endurance test and TGA conditions at higher temperature range. In addition, LCP molecular chains align themselves when moulded, and this generates a self-reinforcing effect, thereby resulting in high mechanical and electrical stress resistance. In this round robin, two LCP materials (LCP sample A, LCP sample B) were chosen for test samples which already have the conventional heat oven ageing data of dielectric strength, tensile strengt
