ASTM_D_6042_-_09.pdf

Designation:D604209Standard Test Method forDetermination of Phenolic Antioxidants and Erucamide SlipAdditives in Polypropylene Homopolymer FormulationsUsing Liquid Chromatography(LC)1This standard is issued under the fixed designation D6042;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.1.Scope*1.1 This test method covers a liquid-chromatographic pro-cedure for the separation of some additives currently used inpolypropylene.These additives are extracted with a cyclo-hexane:methylene chloride mixture using either reflux orultrasonic bath prior to liquid-chromatographic separation.Theultraviolet absorbance(200 nm)of the compound(s)ismeasured,and quantitation is performed using the internalstandard method.1.2 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.Specific precau-tionary statements are given in Section 9.NOTE1There is no known ISO equivalent to this test method.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-ticsE131 Terminology Relating to Molecular SpectroscopyE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodIEEE/ASTM SI-10 Practice for Use of the InternationalSystem of Units(SI)(the Modernized Metric System)3.Terminology3.1 For definitions of plastic terms used in this test method,see Terminologies D883 and D1600.3.2 For the units,symbols,and abbreviations used in thistest method,refer to Terminology E131 or Practice IEEE/ASTM SI-10.3.3 Abbreviations:3.3.1 LCliquid chromatography.3.3.2 PPpolypropylene.3.4 Trade Names:3.5 Vitamin E-Tocopherol,or 3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-ol.3.6 Irgafos 168Tris(2,4 di-tert-butylphenyl)phosphite.3.7 Irganox 3114Tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate.3.8 Kemamide-Ecis-13-docosenamide or erucamide.3.9 Irganox 1010tetrakismethylene(3,5-di-t-butyl-4-hydroxy hydrocinnamate)methane.3.10 Irganox 1076octadecyl-3,5-di-t-butyl-4-hydroxy hy-drocinnamate.3.11 Tinuvin P2(2-hydroxy-5-methyl phenyl)benzotriaz-ole.4.Summary of Test Method4.1 The PP sample is ground to a 20-mesh particle size(850microns)and extracted by refluxing with a mixture of 75:25methylene chloride:cyclohexane or placing in an ultrasonicbath with the same mixture.4.2 The solvent extract is examined by liquid chromatogra-phy.4.3 Additive concentrations are determined relative to aninternal standard(contained in the solvent)using reverse-phasechromatography(C-18 column)with ultraviolet(UV)detectionat 200 nm.5.Significance and Use5.1 Separation and identification of stabilizers used in themanufacture of polypropylene is necessary in order to correlateperformance properties with polymer composition.This testmethod provides a means to determine erucamide slip,Vitamin1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analytical Methods(D20.70.02).Current edition approved Sept.1,2009.Published September 2009.Originallyapproved in 1996.Last previous edition approved in 2004 as D6042-04.DOI:10.1520/D6042-09.2For 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 E,Irgafos 168,Irganox 3114,Irganox 1010,and Irganox 1076levels in polypropylene samples.This test method is alsoapplicable for the determination of other antioxidants,such asUltranox 626,Ethanox 330,Santanox R,and BHT,but theapplicability of this test method has not been investigated forthese antioxidants.5.2 The additive-extraction procedure is made effective bythe insolubility of the polymer sample in solvents generallyused for liquid chromatographic analysis.5.3 Under optimum conditions,the lowest level of detectionfor a phenolic antioxidant is approximately 2 ppm.NOTE2Other methods that have been used successfully to removeadditives from the plastics matrix include thin film,microwave,ultrasonic,and supercritical fluid extractions.Other methods have been used success-fully to separate additives including SFC and capillary GC.5.4 Irgafos 168 is a phosphite antioxidant.Phosphites areknown to undergo both oxidation and hydrolysis reactions.Less Irgafos 168 will be determin