1、BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06Rubber, raw synthetic Determination of the molecular-mass distribution of solution polymers by gel permeation chromatographyBS ISO 11344:2016 ISO 2016Rubber, raw synthetic Determination of the molecular-mass distributio
2、n of solution polymers by gel permeation chromatographyCaoutchouc synthtique brut Dtermination de la rpartition de la masse molculaire pour les caoutchoucs polymriss en solution par chromatographie par permation de gelINTERNATIONAL STANDARDISO11344Second edition2016-10-15Reference numberISO 11344:20
3、16(E)National forewordThis British Standard is the UK implementation of ISO 11344:2016. It supersedes BS ISO 11344:2004 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee PRI/22, Testing and analysis of rubber.A list of organizations represented on this c
4、ommittee 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 2016ISBN 978 0 580 84007 4ICS 83.
5、040.10Compliance 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 30 November 2016.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS ISO 11
6、344:2016 ISO 2016Rubber, raw synthetic Determination of the molecular-mass distribution of solution polymers by gel permeation chromatographyCaoutchouc synthtique brut Dtermination de la rpartition de la masse molculaire pour les caoutchoucs polymriss en solution par chromatographie par permation de
7、 gelINTERNATIONAL STANDARDISO11344Second edition2016-10-15Reference numberISO 11344:2016(E)BS ISO 11344:2016ISO 11344:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may
8、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 requested from either ISO at the address below or ISOs member body in the country of the r
9、equester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 11344:2016ISO 11344:2016(E)Foreword iv1 Scope . 12 Principle 13 General 14 Reagents and materials . 25 Apparatus . 36 Analytical condi
10、tions . 57 Procedure. 57.1 Solvent degassing 57.2 Calibration 57.3 Preparation of test solution . 77.4 Analysis 88 Expression of results 89 Precision . 910 Test report . 9Annex A (informative) Molecular-mass parameters determined by instrumental software .10Annex B (informative) Calculation of molec
11、ular-mass parameters by manual procedure 14Annex C (informative) Comparison of results obtained by automatic procedure (software) and manual procedure 17Annex D (informative) Precision (only for instrumental software procedure) 18Bibliography .20 ISO 2016 All rights reserved iiiContents PageBS ISO 1
12、1344:2016ISO 11344:2016(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 interested i
13、n 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 Electrotechnical Commis
14、sion (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 documents sho
15、uld be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directivesAttention 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 identify
16、ing 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. www.iso.org/patentsAny trade name used in this document is information given for the convenience of us
17、ers and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword - Supplemen
18、tary informationThe committee responsible for this document is ISO/TC 45, Rubber and rubber products, Subcommittee SC 2, Testing and analysis.This second edition cancels and replaces the first edition (ISO 11344:2004), which has been technically revised by replacing the hazardous o-dichlorobenzene w
19、ith BHT (butylated hydroxy toluene) in the procedure. It also incorporates the Technical Corrigendum ISO 11344:2004/Cor.1:2008.iv ISO 2016 All rights reservedBS ISO 11344:2016INTERNATIONAL STANDARD ISO 11344:2016(E)Rubber, raw synthetic Determination of the molecular-mass distribution of solution po
20、lymers by gel permeation chromatographyWARNING 1 Persons using this International Standard should be familiar with normal laboratory practice. This International Standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to
21、establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions.WARNING 2 Certain procedures specified in this International Standard might involve the use or generation of substances, or the generation of waste, that could constitute a local enviro
22、nmental hazard. Reference should be made to appropriate documentation on safe handling and disposal after use.1 ScopeThis International Standard describes a method for the determination of the molecular mass, expressed as polystyrene, and the molecular-mass distribution of polymers produced in solut
23、ion which are completely soluble in tetrahydrofuran (THF) and which have a molecular-mass range from 5 103to 1 106.It is not the purpose of this International Standard to explain the theory of gel permeation chromatography.2 PrincipleThe molecular components of a polymer are separated on the basis o
24、f macromolecule size on a gel permeation column. A known quantity of a dilute solution of the polymer is injected into a stream of solvent, which carries it through the column at a constant rate. The concentration of the separated molecular components in the solvent stream is measured by a suitable
25、detector. Through the use of a calibration curve, both the number-average molecular mass (Mn) and mass-average molecular mass (Mw) of the material analysed can be determined from the retention time and the corresponding concentration.3 General3.1 Gel permeation chromatography (GPC), which is also kn
26、own as size exclusion chromatography (SEC), is a particular type of liquid chromatography which allows the separation of the various components of a polymer based on molecular size.3.2 The molecules of a polymer do not all have the same mass, but comprise a range of different masses. For this reason
27、, the usual concept of molecular mass is not applicable to polymeric materials. Instead, different average molecular masses are determined as shown in Table 1. ISO 2016 All rights reserved 1BS ISO 11344:2016ISO 11344:2016(E)Table 1 Definitions of various kinds of molecular massMass-average molecular
28、 mass Mw= (NiMi2)/(NiMi)= (AiMi)/AiNumber-average molecular mass Mn= (MiNi)/Ni= Ai/(Ai/Mi)z-Average molecular mass Mz= (NiMi3)/(NiMi2)= (AiMi2)/(AiMi)Peak molecular mass MpMolecular mass at peak maximumwhereNiis the number of molecules having a molecular mass of Mi;Aiis the area of the time-slice th
29、at corresponds to molecular mass Mi.The molecular-mass distribution is an important parameter in determining the properties of the polymer. It may be represented by the polydispersity D given byDMM=wnNOTE Polymers invariably consist of macromolecules with a range of molecular sizes. Even the so-call
30、ed monodisperse polystyrenes have a polydispersity of 1,1 compared to a value of 1,0 for a pure compound with a single molecular mass. As the range of molecular sizes present within the polymer increases, so does the polydispersity.4 Reagents and materials4.1 Tetrahydrofuran (THF), with or without 2
31、,6-di-tert-butyl-4-methylphenol (BHT), solvent for the mobile phase, analytical grade.4.2 THF containing 2,6-di-tert-butyl-4-methylphenol, solvent for sample dissolution, analytical grade (THF containing BHT solution).The solution of 2,6-di-tert-butyl-4-methylphenol (also known as BHT, butylated hyd
32、roxytoluene) in THF is commercially available. For the purpose of this International Standard, the solution is called THF containing BHT.When it is difficult to find this solution in the market, the alternative can be obtained by adding 100 mg to 500 mg of BHT to 1 l of THF. Preparation of this solu
33、tion is also effective when a noticeable peak is not obtained for BHT.4.3 Set of certified polystyrene reference standards (minimum 10), with molecular masses in the range 5 102to 1 107(depending on the sample molecular-mass range) and a very narrow molecular-mass distribution (D 2 400 plates for 15
34、0 mm long columns and 4 800 plates for 300 mm long columns; this is also known as a number of theoretical plates, N, as shown in Figure 1. The following formula is used to calculate the theoretical plate number:NVW=554122,( )ewhereVeis the retention volume to the peak maximum;W1/2is the peak width a
35、t half height using the same units for Veand W.Express the result as the number of theoretical plates of total column length. Column arrangement: two to four columns (150 mm to 300 mm long and 4,6 mm to 8,0 mm ID).Key1 injectionNV=e2e=554122,VWFigure 1 Determination of the number of theoretical plat
36、es N by the half-height method5.1.6 Detector.Various types of detectors may be used, such as differential refractometer or UV.5.1.7 Integrator, capable of integrating at least 150 time-slices during the elution of the polymer being analysed.5.1.8 Personal computer and software, to avoid long and dif
37、ficult manual calculations.5.2 PTFE filters, having a pore size of 0,50 m or 0,45 m.5.3 10 cm3(10 ml) and 250 mm3(250 l) syringes.4 ISO 2016 All rights reservedBS ISO 11344:2016ISO 11344:2016(E)5.4 Autocollector (optional), with glass vials.5.5 Mixer.6 Analytical conditionsFlow rate: 0,2 ml/min to 1
38、,0 ml/min.Injection volume: 100 mm3(100 l) of solution, or a quantity suitable for the volume of the column used.The injection volume shall be matched to the set of columns used. The total injection volume shall not exceed 250 l. The concentration of the sample solution injected shall be 0,1 g/l to
39、5,0 g/l.Column temperature: 40 C - 45 C.7 Procedure7.1 Solvent degassingDegass 1 dm3of solvent under vacuum and/or in an ultrasonic bath for about 30 min.To obtain a constant baseline, degassing should preferably be done 12 h before use. From time to time, the columns should be flushed, for a period
40、 of 8 h, with THF solvent, degassed as specified in this subclause, to remove any peroxides left in the column.If an automatic online degassing system is available, the degassing operation given in this subclause can be omitted.7.2 Calibration7.2.1 Use polystyrene standards (4.3) dissolved in THF co
41、ntaining BHT solution (4.2) for calibration purposes. To ensure constant peak size, weigh out a different amount of each individual standard as a function of its molecular mass, for example 1 g/l 0,025 g in 25 cm3of solution (4.2) for molecular masses around 1 000 000, 5 g/l 0,125 g in 25 cm3of solu
42、tion (4.2) for molecular masses lower than 30 000. The calibration plot shall cover the entire range of molecular masses present in the polymer being analysed.7.2.2 Shake the solutions gently.7.2.3 Filter each solution through a PTFE filter (5.2) attached to a 10 cm3syringe.NOTE The reference standa
43、rd solutions can be kept in a refrigerator at 6 C to 7 C for a maximum of 3 months.7.2.4 The calibration procedure described in 7.2.4.1 to 7.2.4.5 is given by way of example.7.2.4.1 Prepare 11 solutions of polystyrene in accordance with Table 3. ISO 2016 All rights reserved 5BS ISO 11344:2016ISO 113
44、44:2016(E)Table 3 Solutions of polystyrene reference standardsSolution No.Concentrationg in 25 cm3of BHT solution (4.2)Actual molecular mass M1 0,025 1 030 0002 0,025 770 0003 0,030 336 0004 0,050 210 0005 0,050 156 0006 0,075 66 0007 0,125 30 3008 0,125 22 0009 0,125 11 60010 0,125 7 00011 0,125 5
45、0507.2.4.2 When using manual injection, draw off 250 mm3(250 l) from each vial, flush the injection loop and then inject 100 l. Read off the retention time corresponding to the peak for each standard. With an automatic sampler, follow the manufacturers instructions. Repeat calibration if necessary.7
46、.2.4.3 In the case of repeat, average the replicates retention times of BHT averaged over all the runs.7.2.4.4 Plot the average retention time, in minutes, against the corresponding value of log(Mi) for each standard and calculate the best-fit line (see Figure 2).7.2.4.5 The correlation coefficient
47、shall be higher than 0,999 5. If not, repeat the calibration procedure for the standards that are causing imperfect alignment, found by computing the difference between the certified (actual) molecular masses and the molecular masses calculated (see Table 4) using the third-degree polynomial represe
48、nting the best-fit line in Figure 2.For the data plotted in Figure 2, the best-fit line is given by the following third-degree polynomial:log(Mi) = 17,569 426 28 1,027 363 146 ti+ 0,030 450 485 ti2 0,000 344 616 ti3For these data, the correlation coefficient is 0,999 53.6 ISO 2016 All rights reserve
49、dBS ISO 11344:2016ISO 11344:2016(E)Table 4 Calibration data corresponding to plot in Figure 2Actual molecular mass MiRetention time timinCalculated molecular mass1 030 000 22,08 1 049 591770 000 22,89 749 228336 000 25,15 323 397210 000 26,15 231 316156 000 27, 58 147 04566 000 30,18 66 95530 300 32,76 29 97822 000 33,68 22 03911 600 35,46 11 5427 000 36,64 7 1635 050 37,47 4 979KeyX retention time (min)Y log(Mi)Figure 2 Calibration plot7.3 Preparation of t
