1、BSI Standards Publication Determination of long-term radiation ageing in polymers Part 1: Techniques for monitoring diffusion-limited oxidation PD IEC/TS 61244-1:2014National foreword This Published Document is the UK implementation of IEC/TS 61244-1:2014. It supersedes BS 7816-1:1995 which is withd
2、rawn. The UK participation in its preparation was entrusted to Technical Committee GEL/112, Evaluation and qualification of electrical insulating materials and systems. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purpor
3、t to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2014. Published by BSI Standards Limited 2014 ISBN 978 0 580 84311 2 ICS 17.240; 29.035.20 Compliance with a British Standard cannot confer immunity from lega
4、l obligations. This Published Document was published under the authority of the Standards Policy and Strategy Committee on 30 September 2014. Amendments/corrigenda issued since publication Date Text affected PUBLISHED DOCUMENT PD IEC/TS 61244-1:2014IEC TS 61244-1 Edition 2.0 2014-08 TECHNICAL SPECIF
5、ICATION SPECIFICATION TECHNIQUE Determination of long-term radiation ageing in polymers Part 1: Techniques for monitoring diffusion-limited oxidation Dtermination du vieillissement long terme sous rayonnement dans les polymres Partie 1: Techniques pour contrler loxydation limite par diffusion INTERN
6、ATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE X ICS 17.240; 29.035.01 PRICE CODE CODE PRIX ISBN 978-2-8322-1827-3 Registered trademark of the International Electrotechnical Commission Marque dpose de la Commission Electrotechnique Internationale Warning! Make sure th
7、at you obtained this publication from an authorized distributor. Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agr. colour inside 2 IEC TS 61244-1:2014 IEC 2014 CONTENTS FOREWORD. 4 INTRODUCTION . 6 1 Scope 7 2 Profiling techniques to monitor diffusion-l
8、imited oxidation . 7 2.1 General . 7 2.2 Infra-red profiling techniques . 7 2.3 Modulus profiling . 10 2.4 Density profiling 14 2.5 Miscellaneous profiling techniques 16 3 Theoretical treatments of diffusion-limited oxidation . 18 4 Permeation measurements 21 5 Oxygen consumption measurements 21 6 C
9、omparison of theory with experimental results 22 7 Oxygen overpressure technique . 23 8 Summary . 25 Annex A (informative) Derivation of theoretical treatment of diffusion-limited oxidation 26 A.1 General . 26 A.2 Numerical simulation . 29 A.3 Cylindrical and spherical geometries and simulation . 30
10、 A.4 Time dependence of the simulation 35 Bibliography . 37 Figure 1 Relative oxidation as determined from the carbonyl absorbance versus depth away from air-exposed surface of polyolefin material after ageing for 6 days at 100 C (from 18) . 8 Figure 2 Depth distribution of carbonyl groups in irradi
11、ated (0,69 Gy/s) multilayer samples composed of 4, 18, 27 and 44 films of 22 m thickness 9 Figure 3 Micro-FTIR spectrophotometric determination of photoproduct and of residual double-bond profiles in a SBR film photooxidized for 100 h . 10 Figure 4 Schematic diagram of modulus profiling apparatus 11
12、 Figure 5 Modulus profiles of 1,68 mm thick commercial fluoro elastomer samples after air ageing at 5,49 kGy/h and 70 C to the indicated radiation doses (from 15) 12 Figure 6 Modulus profiles of 1,68 mm thick commercial fluoro elastomer samples after air ageing at 0,90 kGy/h and 70 C to the indicate
13、d radiation doses (from 15) 12 Figure 7 Modulus profiles of 1,68 mm thick commercial fluoro elastomer samples after air ageing at 0,14 kGy/h and 70 C to the indicated radiation doses (from 15) 13 Figure 8 Modulus profiles of 1,9 mm thick chloroprene rubber samples following elevated temperature expo
14、sures in the presence of air at 150 C, left plot, and 100 C, right plot (from 10) 13 Figure 9 Experimental density profiles (crosses) for 0,302 cm (left) and 0,18 cm (right) thick EPDM sheets after ageing at 6,65 kGy/h and 70 C in airX-ray microanalysis 14 Figure 10 Effect of total radiation dose on
15、 XMA profile for 2 mm thick EPDM sheet irradiated at 1 kGy/h in air (from 24) 15 PD IEC/TS 61244-1:2014IEC TS 61244-1:2014 IEC 2014 3 Figure 11 XMA profiles of 1 mm thick EPDM sheets after thermal ageingin air (from 24) 16 Figure 12 NMR self-diffusion coefficients versus distance away from sample su
16、rface for low-density polyethylene samples after gamma-irradiation in air or vacuum at 0,6 Gy/sec for the indicated total doses (from 26) 17 Figure 13 Chemiluminescence profile for a polypropylene material after gamma irradiation in air to 0,05 MGy at 2 kGy/h (data from 30) 17 Figure 14 Theoretical
17、oxidation profiles for various values of (indicated in the figure) with = 0,1 . 19 Figure 15 Identical to Figure 14, except that = 10 20 Figure 16 Identical to Figure 14, except that = 1 000 20 Figure 17 Plot of c /( + 1) versus , where c denotes the value of integrated oxidation corresponding to 90
18、 % (from 7, 23) . 21 Figure 18 Apparatus used for irradiation under pressurized oxygen conditions . 24 Figure 19 Tensile elongation (left) and tensile strength (right) data for an EPR material aged at the indicated high and low dose-rates in air and at high dose rate in the pressurized oxygen appara
19、tus of Figure 18 25 Figure A.1 Simplified kinetic scheme used to represent the oxidation of polymers (from 44, 45) . 26 Figure A.2 Typical example of normalized concentration of oxygen for cylindrical shape for =0,01 from 46 31 Figure A.3 Typical example of relative oxygen consumption for cylindrica
20、l shape for =0,01 from 46 . 31 Figure A.4 Typical example of normalized concentration of oxygen for cylindrical shape for =100 from 46 . 32 Figure A.5 Typical example of relative oxygen consumption for cylindrical shape for =100 46 32 Figure A.6 Typical example of normalized concentration of oxygen
21、for spherical shape for =0,01 from 46 33 Figure A.7 Typical example of relative oxygen consumption for spherical shape for =0,01 from 46 . 33 Figure A.8 Typical example of normalized concentration of oxygen for spherical shape for =100 from 46 . 34 Figure A.9 Typical example of relative oxygen consu
22、mption for spherical shape for =100 46 34 Figure A.10 Typical example of time-dependent normalized concentration of oxygen at the centre from for the case of =1 46 . 35 Figure A.11 Typical example of time-dependent normalized concentration of oxygen at the centre from for the case of =50 46 . 36 PD
23、IEC/TS 61244-1:2014 4 IEC TS 61244-1:2014 IEC 2014 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ DETERMINATION OF LONG-TERM RADIATION AGEING IN POLYMERS Part 1: Techniques for monitoring diffusion-limited oxidation FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organiza
24、tion 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. To this end and in addition to other activities, IEC
25、 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 National Committee interested in the subject dealt with
26、 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 (ISO) in accordance with conditions determined by ag
27、reement 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 from all interested IEC National Committees. 3) IE
28、C 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 held responsible for the way in which they are us
29、ed 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. Any divergence between any IEC Publication and the c
30、orresponding 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 to IEC marks of conformity. IEC is not responsible
31、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 individual experts and members of its technical committees
32、 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, this IEC Publication or any other IEC Publications. 8
33、) 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 this IEC Publication may be the subject of patent rig
34、hts. 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. In exceptional circumstances, a technical committee may propose the publication of a technical specification when the required suppor
35、t cannot be obtained for the publication of an International Standard, despite repeated efforts, or the subject is still under technical development or where, for any other reason, there is the future but no immediate possibility of an agreement on an International Standard. Technical specifications
36、 are subject to review within three years of publication to decide whether they can be transformed into International Standards. IEC TS 61244-1, which is a technical specification, has been prepared by IEC technical committee 112: Evaluation and qualification of electrical insulating materials and s
37、ystems. This second edition cancels and replaces the first edition published in 1993 and constitutes a technical revision. PD IEC/TS 61244-1:2014IEC TS 61244-1:2014 IEC 2014 5 This edition includes the following significant technical changes with respect to the previous edition: a) numerical simulat
38、ion of DLO is much improved; b) geometry of samples has been expanded from only the case of the infinite plane to the cylindrical and the spherical cases. The text of this specification is based on the following documents: Enquiry draft Report on voting 112/287/DTS 112/304/RVC Full information on th
39、e voting for the approval of this technical specification can be found in the report 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 61244 series, published under the general title Determinati
40、on of long-term ageing in polymers, can be found on the IEC website. The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the IEC web site under “http:/webstore.iec.ch“ in the data related to the specific publication. At this dat
41、e, the publication will be transformed into an International standard, reconfirmed, withdrawn, replaced by a revised edition, or amended. 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 unders
42、tanding of its contents. Users should therefore print this document using a colour printer. PD IEC/TS 61244-1:2014 6 IEC TS 61244-1:2014 IEC 2014 INTRODUCTION It is usually necessary to estimate the anticipated lifetime of a polymeric material in various usage environments. For extended lifetimes (y
43、ears), this often requires the application of accelerated ageing techniques which typically involve the modelling of results obtained at higher-than-ambient environmental stress levels. For many practical applications, air is present during environmental exposures this usually implies that important
44、 oxidation effects underlie the degradation of the material. Unfortunately, exposure of polymers to air during ageing often results in inhomogeneously oxidized samples, a complication which affects attempts both to understand the oxidation process and to extrapolate accelerated exposures to long-ter
45、m conditions. The most important inhomogeneous oxidation complication involves diffusion-limited oxidation. The significance of this complication in various environments, including thermal 1 1radiation 2 to 4 and ultraviolet 5 has been recognized for many years. Diffusion-limited oxidation can occur
46、 whenever the rate of oxygen consumption in a material is greater than the rate at which oxygen can be resupplied to the interior of the material by diffusion processes from the surrounding air atmosphere. Such instances result in a smooth drop in the oxygen concentration from its equilibrium sorpti
47、on value at the sample surfaces to a diminished or non-existent value in the sample interior. This will usually lead to a heterogeneity in the oxidation across the material, with equilibrium oxidation (e.g. corresponding to air-saturated conditions) occurring at the sample surfaces, and reduced or l
48、ittle oxidation in the interior. The importance of the effect will clearly depend upon the material geometry, coupled with the oxygen consumption rate, the oxygen permeability coefficient and the oxygen partial pressure surrounding the sample 5 to 8. Since the oxygen consumption rate will typically
49、depend upon the environmental stress level (e.g. temperature, radiation dose rate) and both the consumption rate and the permeability coefficient may change as the material degrades 9, 10, the importance of diffusion-limited oxidation will also vary with stress level and degradation. This often implies that the percentage of the sample which is oxidized under acce
