1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 16014-4:2012Plastics Determination ofaverage molecular mass andmolecular mass distribution ofpolymers using size-exclusionchromatographyPart 4: High-temperature methodBS I
2、SO 16014-4:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 16014-4:2012.It supersedes BS ISO 16014-4:2003 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/21, Testing of plastics.A list of organizations rep
3、resented on this 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 2012. Published by BSI StandardsLimited 2012ISBN 978 0 580
4、 65174 8ICS 83.080.01Compliance 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 2012.Amendments issued since publicationDate Text affectedBS ISO 16014-4:2012 ISO 2012
5、Plastics Determination of average molecular mass and molecular mass distribution of polymers using size-exclusion chromatography Part 4: High-temperature methodPlastiques Dtermination de la masse molculaire moyenne et de la distribution des masses molculaires des polymres par chromatographie dexclus
6、ion strique Partie 4: Mesurage aux tempratures levesINTERNATIONAL STANDARDISO16014-4Second edition2012-07-01Reference numberISO 16014-4:2012(E)BS ISO 16014-4:2012ISO 16014-4:2012(E)ii ISO 2012 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2012All rights reserved. Unless otherwise specified, no
7、 part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale
8、 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 16014-4:2012ISO 16014-4:2012(E) ISO 2012 All rights reserved iiiContents PageForeword iv1 Scope 12 Normative references . 13 Terms and definitions . 14 Principle . 15
9、Reagents 15.1 Eluent 15.2 Reagent for column evaluation . 15.3 Molecular mass standards 25.4 Reagent for flow rate marker (internal standard) . 25.5 Additives 26 Apparatus 26.1 General . 26.2 Eluent reservoir . 26.3 Pumping system 26.4 Injector . 26.5 Columns . 26.6 Detector 36.7 Tubing . 36.8 Tempe
10、rature-control unit . 36.9 Recorder and plotter . 36.10 Data-processing system 36.11 Other components 37 Procedure 37.1 Preparation of solutions of molecular mass standards . 37.2 Preparation of sample solutions . 47.3 Preparation of solutions for column performance evaluation 47.4 Setting up the ap
11、paratus . 57.5 Operating parameters 57.6 Number of determinations 58 Data acquisition and processing 59 Expression of results . 610 Precision 610.1 General . 610.2 Experimental conditions . 610.3 Results of round-robin test . 711 Test report . 7Annex A (informative) Further information on applicabil
12、ity of method . 8Annex B (informative) Further information on reagents 9Annex C (informative) Further information on the round-robin test .10Bibliography .14BS ISO 16014-4:2012ISO 16014-4:2012(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national st
13、andards 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 the right to be represented on that committee. International o
14、rganizations, 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.International Standards are drafted in accordance with the rules give
15、n in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75
16、 % of the member bodies casting a vote.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.ISO 16014-4 was prepared by Technical Committee ISO/TC 61, Plas
17、tics, Subcommittee SC 5, Physical-chemical properties.This second edition cancels and replaces the first edition (ISO 16014-4:2003), which has been technically revised. The main changes are as follows:a) the normative references have been updated;b) Subclause 6.1 (concerning the general requirements
18、 for the apparatus) has been revised;c) further information on the round-robin test carried out in 1999 has been added (see Annex C).ISO 16014 consists of the following parts, under the general title Plastics Determination of average molecular mass and molecular mass distribution of polymers using s
19、ize-exclusion chromatography: Part 1: General principles Part 2: Universal calibration method Part 3: Low-temperature method Part 4: High-temperature method Part 5: Method using light-scattering detectioniv ISO 2012 All rights reservedBS ISO 16014-4:2012INTERNATIONAL STANDARD ISO 16014-4:2012(E)Plas
20、tics Determination of average molecular mass and molecular mass distribution of polymers using size-exclusion chromatography Part 4: High-temperature method1 ScopeThis part of ISO 16014 specifies a method for determining the average molecular mass and the molecular mass distribution of polymers by s
21、ize-exclusion chromatography (SEC) using an organic eluent at temperatures between 60 C and 180 C. The average molecular mass and the molecular mass distribution are calculated from a calibration curve prepared using polymer standards. Therefore, this test method is classified as a relative method (
22、see ISO 16014-1:2012, Annex A).2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) appli
23、es.ISO 472, Plastics VocabularyISO 16014-1:2012, Plastics Determination of average molecular mass and molecular mass distribution of polymers using size-exclusion chromatography Part 1: General principlesISO 16014-2, Plastics Determination of average molecular mass and molecular mass distribution of
24、 polymers using size-exclusion chromatography Part 2: Universal calibration method3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 472 and in ISO 16014-1 apply.4 PrincipleSee ISO 16014-1:2012, Clause 4.5 Reagents5.1 EluentFor a general discussion of el
25、uents, see ISO 16014-1:2012, 5.1.For examples of eluents used for SEC measurements at temperatures 60 C, see Annex B.5.2 Reagent for column evaluationSee ISO 16014-1:2012, 5.2. ISO 2012 All rights reserved 1BS ISO 16014-4:2012ISO 16014-4:2012(E)There are several low molecular mass compounds that can
26、 be used, for example diphenylmethane when 1,2-dichlorobenzene is used as eluent or ethylbenzene when 1,2,4-trichlorobenzene is used as eluent.5.3 Molecular mass standardsSee ISO 16014-1:2012, 5.3.Some examples of commercially available molecular mass standards are given in Annex B.5.4 Reagent for f
27、low rate marker (internal standard)See ISO 16014-1:2012, 5.4.An example of a compound suitable for use as a flow rate marker is 2,6-di-tert-butyl-4-methylphenol when 1,2-dichlorobenzene or 1,2,4-trichlorobenzene is used as eluent.5.5 AdditivesPhenol-type antioxidants such as 2,6-di-tert-butyl-4-meth
28、ylphenol should preferably be added to avoid degradation of the polymer sample. For further examples of antioxidants, see Annex B.6 Apparatus6.1 GeneralA schematic diagram of an SEC system is shown in ISO 16014-1:2012, Figure 1.Either commercially available or assembled SEC systems may be used, prov
29、ided they meet the component requirements specified and have the capability to maintain a constant column temperature between 60 C and 180 C. However, components connected upstream of the injector, such as the eluent reservoir, the pumping system and tubing, does not need to be kept at the same temp
30、erature as the columns.6.2 Eluent reservoirSee ISO 16014-1:2012, 6.2.As mentioned in 6.1, it is not necessary to keep the eluent reservoir at the same temperature as the columns.6.3 Pumping systemSee ISO 16014-1:2012, 6.3.In order to maintain the flow rate accurate to within 0,3 %, the pumping syste
31、m shall be kept at a constant temperature. As mentioned in 6.1, it is not, however, necessary to keep the pumping system at the same temperature as the columns.6.4 InjectorSee ISO 16014-1:2012, 6.4.In order to ensure that the polymer solution remains clear, without any precipitation, the injector te
32、mperature-control equipment shall be capable of keeping the injector at the same temperature, to within 1 C, as the columns. As manual injection is impossible at such temperatures, an automatic injection system shall be used.6.5 ColumnsSee ISO 16014-1:2012, 6.5.2 ISO 2012 All rights reservedBS ISO 1
33、6014-4:2012ISO 16014-4:2012(E)Organic or inorganic packing materials may be used, and there are no limitations on particle size or shape except that, when analysing high molecular mass and/or shear-sensitive polymers, the particle size should be large enough for no rupture of the polymer chain to oc
34、cur during elution of the polymers.The set of columns used shall have a theoretical plate number 12 000/m, and the resolution factor R shall be 1,5 close to the polymer peak. The asymmetry factor shall be within the range 1,00 0,15. The set of columns used should preferably cover the whole range of
35、molecular masses being determined, and the calibration curve shall be as linear as possible (the correlation factor shall be very close to 1). Determination of the theoretical plate number, the resolution factor and the asymmetry factor of the columns shall be carried out as described in ISO 16014-1
36、:2012, 6.5.The column temperature-control equipment shall be capable of keeping the columns within 0,5 C of the operating temperature, which shall be between 60 C and 180 C.6.6 DetectorSee ISO 16014-1:2012, 6.6.The detector temperature-control equipment shall be capable of keeping the detector withi
37、n 0,5 C of the temperature set, in order to meet the requirements for flow rate and baseline stability (sensitivity). It is recommended that the columns and detector be kept at the same temperature.6.7 TubingSee ISO 16014-1:2012, 6.7.The temperature of the tubing shall be kept constant and high enou
38、gh to ensure that the column performance requirements are met, but it is not necessary to keep the tubing at the same temperature as the column.6.8 Temperature-control unitOne of the important factors in SEC is that all components need to be kept at a constant temperature and, with the method descri
39、bed in this part of ISO 16014, some of them need to be kept at a high temperature. Therefore, an accurate temperature-control system is essential to meet the performance requirements for SEC.6.9 Recorder and plotterSee ISO 16014-1:2012, 6.9.6.10 Data-processing systemSee ISO 16014-1:2012, 6.10.6.11
40、Other componentsIn addition to the components described above, a column guard filter, a pressure monitor, a pulse damper or related components can be used, if necessary.7 Procedure7.1 Preparation of solutions of molecular mass standardsThe molecular mass standards used to prepare the calibration cur
41、ve should preferably be selected so as to cover the range of molecular masses of the polymer being analysed and so that there are at least two standards in each molecular mass decade. Solutions may be prepared which contain more than one narrow molecular mass distribution standard, but only if the s
42、tandards are perfectly separated from each other on the chromatogram. Solutions of standards of molecular mass 1 000 000 shall be prepared separately. ISO 2012 All rights reserved 3BS ISO 16014-4:2012ISO 16014-4:2012(E)If molecular mass standards having the same chemical structure as the polymer bei
43、ng analysed are not available, the calibration curve may be prepared using standards consisting of a different type of polymer, and a universal calibration curve prepared for this different type of polymer (see ISO 16014-2).If gentle shaking and/or stirring or heating is required to accelerate disso
44、lution, the duration shall be as short as possible to avoid any rupture of the polymer chains.Filtration of the solutions is recommended to protect the column from clogging. In such cases, membrane filters or sintered-metal filters with a pore size between 0,2 m and 1 m shall be used. If solid mater
45、ial is observed on the filter, indicating incomplete dissolution, repeat the dissolution process. If a membrane filter is used, the membrane and backing shall be inert to the solvent being used.In general, use solutions within 48 h of preparation. However, longer storage times are allowed if the sol
46、ution is kept in a cool, dark place to prevent polymer degradation and solvent evaporation.Recommended concentrations for solutions of molecular mass standards are as follows:Mp105have a slow rate of dissolution, however, and it might be necessary to continue beyond 30 min to ensure complete dissolu
47、tion. Filtration of solutions is recommended to avoid clogging of the column.If solid material is observed on the filter, indicating incomplete dissolution, repeat the dissolution process. Following preparation, transfer sample solutions to vials and store at room temperature.The sample must be heat
48、ed sufficiently to dissolve it completely. Excessive or long heating shall be avoided, however, as this might lead to thermal or oxidative degradation. The optimum dissolution temperature and time should preferably be determined experimentally. For example, except for high molecular mass or high-den
49、sity samples, polyethylene can be dissolved in 1,2-dichlorobenzene by heating at 140 C for 1,5 h. Polyethylene with a molecular mass 106is more difficult to dissolve, requiring higher temperatures and longer times.Before injection, sample solutions may be kept at a temperature between room temperature and the dissolution temperature. The temperature of the injector shall be sufficiently high, and the dwell time of the solution in the injector sufficiently long, to ensure that the sample remains dissolved and n
