ASTM_D_3156_-_96_2016.pdf

Designation:D315696(Reapproved 2016)Standard Practice forRubberChromatographic Analysis of Antidegradants(Antioxidants,Antiozonants and Stabilizers)1This standard is issued under the fixed designation D3156;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.Scope1.1 This practice covers the detection and identification bythin-layer chromatography of antidegradants(antioxidants,antiozonants,and stabilizers)that may be present in raw rubberor rubber products.Analysis for other types of antidegradantsis possible as long as the requirements of the practice are met.1.2 The values stated in SI units are to be regarded as thestandard.1.3 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 Document2.1 ASTM Standards:2D297 Test Methods for Rubber ProductsChemical Analy-sis3.Summary of Practice3.1 A simplified procedure(Method A,Section 13.1)basedon a single-solvent system is presented,which provides for theidentification of known materials.This may be used to checkthe presence or absence in a rubber vulcanizate or raw rubber,of an antidegradant which should be present.However,sincethe chromatograms obtained may not be absolutely specific forany given antidegradant,a more detailed scheme is given in13.2.3.2 Method B,Section 13.2,using additional solvents andsprays is included,which enables a greater degree of separationof the spots to be made and therefore may enable detection andidentification of an unknown antidegradant.3.3 Other techniques,for example:gas chromatographic(with or without treatment to obtain derivatives),spectroscopic(ultraviolet and infrared),more sophisticated thin-layer varia-tions(two dimensional techniques),may be applied to identi-fication of spots for improved detection and identification of anunknown antidegradant.3.4 It is possible that the chromatographic pattern of oneantidegradant may overlap that of another antidegradant;therefore each laboratory must prepare its own referencestandards,based on the technique chosen from this practice.4.Significance and Use4.1 This practice is useful for the examination of rubbercompounds or products for the presence of chemicals thatprevent or greatly reduce degradation due to oxygen,ozone,orother agents.4.2 This practice is suitable for quality assurance,factorycontrol,and research and development applications.5.Interferences5.1 In the absence of extender oils,antidegradants areextracted from the rubber by a solvent and the evaporatedextract is applied directly to a thin-layer chromatographicplate.5.2 In the presence of extender oils,the oils are removed byeither a pre-treatment of the plate,with light petroleum ether orby a column chromatographic technique.5.3 Identification of the antidegradant is made by thestandard technique of thin-layer chromatography,herein de-scribed.6.Apparatus6.1 Spreading Device,for making thin layer chromato-graphic plates with a coating 250 to 300 m thick.6.2 Glass Plates,200 by 200-mm,or suitable for theselected tank.As an alternative to preparing plates,the use ofprecoated plates with a coating of 250 to 300 m is permitted.Precoated film-backed plates are not recommended.6.3 Drying Oven,105C minimum.1This practice is under the jurisdiction ofASTM Committee D11 on Rubber andis the direct responsibility of Subcommittee D11.11 on Chemical Analysis.Current edition approved June 1,2016.Published June 2016.Originallyapproved in 1973.Last previous edition approved in 2011 as D3156 96(2011).DOI:10.1520/D3156-96R16.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.4 Desiccator,or drying box for storing plates at fixedhumidity.6.5 Micro-pipets,5 and 10-mm3(L).6.6 Chromatographic Developing Tank,of a size suitable tohold plates,approximately 250 by 250 by 70 mm to 330 by 240by 110 mm.Small“sandwich-type”tanks are not recom-mended.Add about 200 cm3of developing solvent(7.4)to thetank,swirl,cover,and allow to stand 15 min before using.Tankmay be reused by repeating the swirling and standing step,aslong as the solvent ratio remains constant.6.7 Extraction Apparatus,in accordance with Section 18 or25 of Test Methods D297.6.8 Chromatographic Columns,short,liquid-solid.Thosefound satisfactory are as follows:6.8.1 Hypodermic Syringe Barrel,5-cm3,fitted with aneedle about 35