BS ISO BRITISH STANDARD 16564:2004 Incorporating Amendment No. 1 Rubber, raw natural Determination of averagemolecularmass and molecular-mass distribution by size exclusion chromatography (SEC) ICS 83.040.10 BSi NOCOPYINGWITHOUTBSIPERMISSIONEXCEPTASPERMITTEDBYCOPYRIGHTLAW British Standards BS ISO 16564:2004 National foreword This British Standard reproduces verbatim ISO 16564:2004, including amendment May 2006, and implements it as the UK national standard. The startandfinishoftextintroducedoralteredbyamendmentisindicatedin the text by tags : --. Tags indicating changes to ISO text carry the number ofthe amendment. For example, text altered by ISO amendment 1 is indicated in the text by! The UK participation in its preparation was entrusted to Technical Committee PRI/23, Test methods for rubber and non-black compounding ingredients, which has the responsibility to: aidenquirerstounderstandthetext; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled "International Standards Correspondence Index", or by using the “Search" facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not ofitself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to iv, pages 1 to 8, and inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication This British Standard was published under the authority Amd. No. Date Comments of the Standards Policy and Strategy Committee on 16463 30 June 2006 See national foreword 1November2004 BSI2006 ISBN 0 580 44709 X BS ISO 16564:2004 INTERNATIONAL ISO STANDARD 16564 First edition 2004-10-01 Rubber, raw natural Determination of average molecular mass and molecular- mass distribution by size exclusion chromatography (SEC) Caoutchouc naturel brutDétermination de la massemoléculaire moyenne et de la repartition des masses moleculaires par chromatographied'exclusionsterique(SEC) Reference number ISO 16564:2004(E) ii BS IS0 16564:2004 Contents Page Foreword 1 Scope. 2 Principle . 3 Materials 4 Apparatus. 5 Procedure. 6 Calibration. 7 Expression of results. .5 8 Precision ... 9 Test report... Annex A (informative) SEC analysis of natural rubber using cyclohexane as solvent and polyisoprene standards.. Bibliography ili iv BS IS0 16564:2004 Rubber, raw natural Determination of average molecular mass and molecular-mass distribution by size exclusion chromatography (SEC) WARNING - Persons using this International Standard should be familiar with normal laboratory practice. This standard does not purport to address all of the safety problems, if any, associated with 1 Scope This International Standard specifies a method of determining the average molecular mass and the molecular- mass distribution of raw natural rubber dissolved in tetrahydrofuran. A set of polystyrene standards is used for calibration purposes (i.e. the method is a relative one). An alternative method, using cyclohexane as solvent and polyisoprene standards, is included in an informative annex. 2 Principle Dried natural rubber is dissolved in tetrahydrofuran at room temperature. The solution is filtered to remove “gel" (slightly crosslinked rubber) and other insoluble materials. The filtrate is used to det