ASTM_D_3452_-_06_2012.pdf

Designation:D345206(Reapproved 2012)Standard Practice forRubberIdentification by Pyrolysis-Gas Chromatography1This standard is issued under the fixed designation D3452;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.PART 1.IDENTIFICATION OF SINGLE POLYMERS1.Scope1.1 This practice covers the identification of polymers inraw rubbers,and cured and uncured compounds,based on asingle polymer,by the gas chromatographic patterns of theirpyrolysis products(pyrograms).Implementation of this guidepresupposes a working knowledge of the principles and tech-niques of gas chromatography,sufficient to carry out thispractice and to interpret the results correctly.21.2 This practice will identify the following polymers:1.2.1 Polyisoprene of natural or synthetic origin,1.2.2 Butadiene-styrene copolymers,1.2.3 Polybutadiene,1.2.4 Polychloroprene,1.2.5 Butadiene-acrylonitrile copolymers,1.2.6 Ethylene-propylenecopolymersandrelatedterpolymers,and1.2.7 Isobutene-isoprene copolymers.1.3 This practice will not differentiate the following poly-mers:1.3.1 Natural polyisoprene from synthetic polyisoprene.1.3.2 Butadiene-styrene copolymers produced by solutionand emulsion polymerization.It is sometimes possible todistinguish butadiene-styrene copolymers containing differentamounts of styrene as well as random polymers from blockpolymers.1.3.3 Polybutadiene with different microstructures.1.3.4 Different types of polychloroprenes.1.3.5 Butadiene-acrylonitrile copolymers with differentmonomer ratios.1.3.6 Ethylene-propylene copolymers with different mono-mer ratios,as well as the copolymers from the related terpoly-mers.1.3.7 Isobutene-isoprene copolymers(butyl rubbers)fromhalogenated butyl rubbers.1.3.8 Polyisoprene containing different amounts of cis-transisomers.1.3.9 The practice does not identify ebonite or hard rubbers.1.4 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3D297 Test Methods for Rubber ProductsChemical Analy-sisE260 Practice for Packed Column Gas ChromatographyE355 Practice for Gas Chromatography Terms and Relation-ships3.Significance and Use3.1 For research,development,and quality controlpurposes,it is advantageous to determine the composition ofrubbers in cured,compounded products.3.2 This practice provides such composition analysis,uti-lizing a gas chromatograph and pyrolysis products from rubberdecomposition.4.Principle of the Practice4.1 This practice is based upon comparison of the gaschromatographic pattern of the pyrolysis products of a known1This practice is under the jurisdiction ofASTM Committee D11 on Rubber andis the direct responsibility of Subcommittee D11.11 on Chemical Analysis.Current edition approved Aug.1,2012.Published May 2013.Originallyapproved in 1975.Last previous edition approved in 2006 as D3452 06.DOI:10.1520/D3452-06R12.2Definitions of terms and general directions for the use of gas chromatographymay be found in Practices E355 and E260.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 rubber with an unknown rubber.The results of this separationwill hereafter be referred to as the pyrogram.4.2 The pyrogram of the known rubber is filed for futurereference.The pyrogram of the unknown rubber is compared tothis for identification.4.3 The success of the method depends upon examining theknown and unknown rubbers under exactly the same experi-mental conditions.4.4 The qualitative composition of the pyrolysis productsdepend upon the type of polymer being studied.4.5 The quantitative composition of the pyrolysis productsmay be affected by the degree of cure,and recipe used,etc.,butthe most important factor is the type of pyrolysis device.5.Apparatus5.1 Pyrolysis DevicesThe applicability of this practice hasbeen checked on the following types:5.1.1 Quartz Tubes,electrically heated at a prefixed tem-perature.The volatile products enter the chromatographthrough heated tubing.5.1.2 Platinum Filaments,electrically heated.Pyrolysis iscarried out within the chromatograph inlet and immediatelyswept into the column b