ASTM_D_4676_-_94_2021.pdf

Designation:D467694(Reapproved 2021)Standard Classification forRubber Compounding MaterialsAntidegradants1This standard is issued under the fixed designation D4676;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 classification covers antidegradants used in rubberand where appropriate defines their important chemical andphysical characteristics for use in rubber.1.2 The general term“antidegradant”describes materialsused in rubber to protect against the effects of oxygen andozone.Materials that fall in this general category include bothantioxidants and antiozonants.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1218 Test Method for Refractive Index and RefractiveDispersion of Hydrocarbon LiquidsD1519 Test Methods for Rubber ChemicalsDeterminationof Melting RangeD1747 Test Method for Refractive Index of Viscous Mate-rialsD2702 Practice for Rubber ChemicalsDetermination ofInfrared Absorption CharacteristicsD3461 Test Method for Softening Point ofAsphalt and Pitch(Mettler Cup-and-Ball Method)D4571 Test Methods for Rubber Compounding MaterialsDetermination of Volatile MaterialD4574 Test Methods for Rubber Compounding MaterialsDetermination of Ash ContentD4937 Test Method forp-Phenylenediamine AntidegradantsPurity by Gas ChromatographyD5376 Test Method for Rubber Compounding MaterialsDetermination of the Basic Nitrogen Content in RubberAntioxidant:Polymerized TMQE28 Test Methods for Softening Point of Resins Derivedfrom Pine Chemicals and Hydrocarbons,by Ring-and-Ball Apparatus3.Significance and Use3.1 There are many different antidegradants available foruse in the rubber industry.3.2 This classification of the various materials covers theirchemical structure along with a brief reference to their overalluse and their properties.4.Basis of Classification4.1 Rubber antidegradants included in this classificationdocument are divided into the six classes shown below.Theclassification in general is based on the chemical structurecategorization but in most cases it also classifies the materialsaccording to their potential rubber applications.4.2 Class 1,p-Phenylenediamines(PPDs)This group ofadditives represents the primary materials used in tires andother mechanical goods to impart ozone protection.Theseadditives are also used as antioxidants and antiflex agents in anumber of applications but are considered to be stronglystaining and thus limited to black rubber applications.They canalso be used as raw polymer stabilizers.4.2.1 Although all PPDs have similar performancecharacteristics,the different types are frequently preferred forcertain end use conditions;for example,selection is based onthe type and degree of flexing to be experienced by the rubberarticle.4.3 Class 2,Trimethyl-dihydroquinolines(TMQs)Thesematerials are primarily used to protect rubber articles fromdegradation by atmospheric oxygen at higher temperatures.They are moderately staining.1This classification is under the jurisdiction of ASTM Committee D11 onRubber and Rubber-like Materials and is the direct responsibility of SubcommitteeD11.20 on Compounding Materials and Procedures.Current edition approved Nov.1,2021.Published January 2022.Originallyapproved in 1987.Last previous edition approved in 2017 as D4676 94(2017).DOI:10.1520/D4676-94R21.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1?4.3.1 Although all TMQs have similar performancecharacteristics,different types are frequently preferred toaccommodate processing or end use needs.4.4 Class 3,PhenolicsPhenolic antidegradants represent agroup of“n