1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 16014-1:2012Plastics Determination ofaverage molecular mass andmolecular mass distribution ofpolymers using size-exclusionchromatographyPart 1: General principlesBS ISO 16
2、014-1:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 16014-1:2012.It supersedes BS ISO 16014-1:2003 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/21, Testing of plastics.A list of organizations represen
3、ted 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 6517
4、1 7ICS 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 16014-1:2012 ISO 2012Plast
5、ics Determination of average molecular mass and molecular mass distribution of polymers using size-exclusion chromatography Part 1: General principlesPlastiques Dtermination de la masse molculaire moyenne et de la distribution des masses molculaires des polymres par chromatographie dexclusion striqu
6、e Partie 1: Principes gnrauxINTERNATIONAL STANDARDISO16014-1Second edition2012-07-01Reference numberISO 16014-1:2012(E)BS ISO 16014-1:2012ISO 16014-1:2012(E)ii ISO 2012 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2012All rights reserved. Unless otherwise specified, no part of this publicatio
7、n 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 56 CH-1211 Geneva 20Tel
8、. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 16014-1:2012ISO 16014-1:2012(E) ISO 2012 All rights reserved iiiContents PageForeword iv1 Scope 12 Normative references . 13 Terms and definitions . 14 Principle . 35 Reagents 35.1 Eluent 35.
9、2 Reagent for column evaluation . 35.3 Molecular mass standards 35.4 Reagent for flow rate marker (internal standard) . 45.5 Additives 46 Apparatus 46.1 General . 46.2 Eluent reservoir . 46.3 Pumping system 46.4 Injector . 56.5 Columns . 56.6 Detector 76.7 Tubing . 86.8 Temperature control . 86.9 Re
10、corder and plotter . 86.10 Data-processing system 86.11 Other components 87 Procedure 88 Data acquisition and processing 88.1 Data acquisition . 88.2 Evaluation of data and correction of chromatograms 98.3 Data processing . 99 Expression of results .109.1 Calibration curve .109.2 Calculation of aver
11、age molecular mass 119.3 Differential molecular mass distribution curve .129.4 Cumulative molecular mass distribution curve 1310 Precision 1311 Test report .1411.1 General .1411.2 Apparatus and measurement parameters 1411.3 Calibration of the system 1411.4 Calibration curve .1411.5 Results .15Annex
12、A (informative) Supplementary information .16Annex B (informative) Narrow molecular mass distribution standards 17BS ISO 16014-1:2012ISO 16014-1:2012(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The wor
13、k 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 organizations, governmental and non-governme
14、ntal, 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 given in the ISO/IEC Directives, Part 2.The mai
15、n 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 % of the member bodies casting a vote.Atte
16、ntion 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 16014-1 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 5, Physical-chemical
17、properties.This second edition cancels and replaces the first edition (ISO 16014-1:2003), which has been technically revised. The main changes are the following:a) the normative references have been updated (see Clause 2);b) the text has been adapted to allow for the fact that a new part, ISO 16014-
18、5, has now been published;c) Subclause 6.5 (concerning the chromatographic columns used) has been revised;d) Subclause 8.2 (concerning the evaluation of data and the correction of chromatograms) has been revised.It also incorporates the Technical Corrigendum ISO 16014-1:2003/Cor.1:2005.ISO 16014 con
19、sists of the following parts, under the general title Plastics Determination of average molecular mass and molecular mass distribution of polymers using size-exclusion chromatography: Part 1: General principles Part 2: Universal calibration method Part 3: Low-temperature method Part 4: High-temperat
20、ure method Part 5: Method using light-scattering detectioniv ISO 2012 All rights reservedBS ISO 16014-1:2012INTERNATIONAL STANDARD ISO 16014-1:2012(E)Plastics Determination of average molecular mass and molecular mass distribution of polymers using size-exclusion chromatography Part 1: General princ
21、iples1 ScopeThis part of ISO 16014 specifies a general method for determining the average molecular mass and the molecular mass distribution of polymers using size-exclusion chromatography (SEC). The average molecular mass and the molecular mass distribution are calculated from a calibration curve c
22、onstructed using polymer standards if using one of the SEC techniques described in Parts 2 to 4 of this International Standard or from a calibration curve constructed using absolute molecular mass data if using size-exclusion chromatography coupled with light-scattering detection (SEC-LS) as describ
23、ed in Part 5 of this International Standard.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 amen
24、dments) applies.ISO 472, Plastics VocabularyISO 16014-2:2012, Plastics Determination of average molecular mass and molecular mass distribution of polymers using size-exclusion chromatography Part 2: Universal calibration methodISO 16014-3, Plastics Determination of average molecular mass and molecul
25、ar mass distribution of polymers using size-exclusion chromatography Part 3: Low-temperature methodISO 16014-4, Plastics Determination of average molecular mass and molecular mass distribution of polymers using size-exclusion chromatography Part 4: High-temperature methodISO 16014-5:2012, Plastics D
26、etermination of average molecular mass and molecular mass distribution of polymers using size-exclusion chromatography Part 5: Method using light-scattering detection3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 472 and the following apply.3.1size-e
27、xclusion chromatographySECa liquid chromatographic technique in which the separation is based on the hydrodynamic volume of molecules eluting in a column packed with porous non-adsorbing material having pore dimensions that are similar in size to the molecules being separatedNOTE The term gel permea
28、tion chromatography (GPC) should only be used where the porous non-adsorbing packing material is a gel; however, the term size-exclusion chromatography (SEC) is preferred. ISO 2012 All rights reserved 1BS ISO 16014-1:2012ISO 16014-1:2012(E)3.2light-scattering detectionLS detectiona technique for det
29、ermining the mass or size of polymer molecules dissolved in solution by measuring the light scattered by the polymer molecules3.3molecular massMsum of the masses of the atoms making up a moleculeNOTE Molecular weight is also used for molecular mass, but is deprecated.3.4average molecular massfour ty
30、pes of average molecular mass are defined by the following equations, where Niis the number of molecules of species i of molecular mass Miand a is the exponent of the Mark-Houwink-Sakurada equation.3.4.1number-average molecular massMnMNMNiiiiin=()11(1)3.4.2mass-average molecular massMwMNMNMiiiiiiw=(
31、)()211(2)3.4.3z-average molecular massMzMNMNMiiiiiiz=()()3121(3)3.4.4viscosity-average molecular massMvMNMNMiiaiiiiav=+=()()/1111(4)2 ISO 2012 All rights reservedBS ISO 16014-1:2012ISO 16014-1:2012(E)4 PrincipleA polymer sample is dissolved in a suitable solvent to make a dilute solution. This solut
32、ion is injected into the mobile phase and onto the SEC column, which is packed with non-adsorbing material made up of small particles having pores of similar or varying size. As the polymer sample passes through the column, the polymer molecules are separated from each other according to the differe
33、nce in their molecular masses, or more precisely, the difference in their molecular sizes (i.e. their hydrodynamic volume). In SEC, the larger-size molecules cannot permeate into the pores, and thus elute faster, while smaller molecules can permeate into the pores and elute more slowly. The polymer
34、concentration in the eluate is continuously monitored by a concentration-sensitive detector (coupled to a light-scattering detector if SEC-LS is being used) to give an SEC chromatogram.In the SEC techniques described in Parts 2 to 4, the molecular mass at any elution time on the SEC chromatogram is
35、determined from a calibration curve which is constructed using reference polymer standards with a narrow molecular mass distribution. In SEC-LS, described in Part 5 of this International Standard), a calibration curve constructed using absolute molecular mass data obtained from the SEC-LSchromatogra
36、m at any elution time is used. The average molecular mass and the molecular mass distribution of the unknown polymer are calculated by using the molecular mass and concentration data corresponding to each elution time.5 Reagents5.1 EluentThe required purity of the eluent used for SEC varies with the
37、 application, but in general the solvent should be free of particulate matter and substances that react with the polymer or interfere with detection of the polymer. Additives such as antioxidants and salts can be used to prevent the degradation of the eluent, the aggregation of polymer molecules, th
38、e adsorption of the polymer on the packing material and for other purposes. A mixed eluent may also be used in the SEC techniques described in Parts 2 to 4 to modify the solubility and the refractive index, or to reduce the cost of the mobile phase. A mixed eluent cannot be used for SEC-LS measureme
39、nts, however, because the polymer selectively adsorbs the components of the mixed eluent, thus giving an erroneous result.5.2 Reagent for column evaluationA low molecular mass compound is used for the determination of the theoretical plate number, asymmetry factor and resolution factor of the column
40、.5.3 Molecular mass standardsThe test methods described in Parts 2 to 4 of this International Standard are not absolute methods but relative ones, and require a calibration curve for the calculation of the average molecular mass and the molecular mass distribution from the SEC chromatogram. This cal
41、ibration curve is plotted using standards of known molecular mass and narrow molecular mass distribution. The value of Mwand/or Mnof the standard determined by an absolute method, such as light scattering, membrane osmometry, vapour pressure osmometry, ultracentrifugation or end-group analysis. The
42、polydispersity Mw/Mnis calculated by dividing the absolute value of Mwby the absolute value of Mn. The polydispersity of the polymer standards shall lie within the following ranges:Mp30 % of the total polymer peak area, as shown in Figure 4 c), the method described in this part of ISO 16014 is not r
43、ecommended.NOTE The detector response might vary at low molecular mass, and the presence of a significant proportion of low molecular mass material makes any calculation unreliable. ISO 2012 All rights reserved 9BS ISO 16014-1:2012ISO 16014-1:2012(E)a)b)c)Key1 system peakFigure 4 Typical SEC curves9
44、 Expression of results9.1 Calibration curveFor the SEC methods described in Parts 2 to 4 of this International Standard, prepare the calibration curve by plotting elution times against lgMpas shown in Figure 5. The values of Mpare obtained in one of the following ways:a) from the data sheets for the
45、 standard materials;b) by calculation, using Equation (5), from the values of Mwand Mngiven in the data sheets for the standard materials;c) by calculation, using Equation (5), from the values of Mwor Mnand Mw/Mngiven in the data sheets for the standard materials.10 ISO 2012 All rights reservedBS IS
46、O 16014-1:2012ISO 16014-1:2012(E)Polynomials containing terms up to t3are widely used to describe calibration curves. The addition of higher powers might improve the fit of the curve to the data:lgMA At=+01(10)lgMA At At At=+01 2233(11)whereM is the molecular mass;A0, A1, A2, A3are coefficients;t is
47、 the elution time.Other methods, or a combination of methods, may be used to improve the fit.For the preparation of a universal calibration curve, see ISO 16014-2:2012, 9.1. For the preparation of a calibration curve for SEC-LS, see ISO 16014-5:2012, 11.1.Keyt elution time (min)lgM natural logarithm
48、 of the molecular massFigure 5 Calibration curve9.2 Calculation of average molecular massCalculate the molecular mass Miand signal intensity Hiat each elution time using the calibration curve (see 9.1) and the SEC chromatogram of the polymer sample for which the baseline and the calculation range ha
49、ve been determined (see 8.3.1 and 8.3.2), as follows:a) calculate the molecular mass Miat the ith elution time tiby inserting tiin Equation (10) or Equation (11);b) calculate the signal intensity Hiat the ith elution time tiby subtracting the baseline signal intensity from the total detector signal intensity at the elution time ti. ISO 2012 All rights reserved 11BS ISO 16014-1:2012ISO 16014-1:2012(E)The average molecular mass and the polydispersity can be calculated
