ASTM_D_8471_-_22a.pdf

Designation:D847122aStandard Practice forSilicaReference Compound1This standard is issued under the fixed designation D8471;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 standard raw materials,formulation,and mixing procedure for the evaluation andquality control of silica and related technologies,such assilanes and functionalized polymers,in a standardized rubbercompound.1.2 UnitsThe values stated in SI units are to be regardedas the standard.No other units of measurement are included inthis standard.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:2D1566 Terminology Relating to RubberD3182 Practice for RubberMaterials,Equipment,and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized SheetsD5900 Specification for Physical and Chemical Properties ofIndustry Reference Materials(IRM)3.Terminology3.1 The following terms are defined in accordance withTerminology D1566.3.2 Definitions:3.2.1 silanization,nchemical reaction of organosilanemolecules with the silanol groups of synthetic amorphous silicacovering its surface and improving its compatibility withrubber leading to an enhanced dispersion.3.2.2 silica(asrelatedtorubbertechnology),nnanostructured,synthetic amorphous silicon dioxide(SAS)typically based on primary particles bound to form aggregatesand agglomerates as secondary particles,covered by silanolsand siloxanes,and produced either by conversion to a solidfrom a supersaturated solution of silicate salts in water(pre-cipitated SAS),or by a pyrogenic process in a flame(fumedSAS).4.Summary of Practice4.1 This practice shall be used for specific procedures usedin silica technology for rubber compounds.A reference com-pound is required for quality control of production,for researchand development purposes,and for comparison of differentmaterials.5.Significance and Use5.1 This practice may be used to characterize silica or silanein terms of specific properties of the standard compound.Thispractice is useful for the quality assurance of silica production.It may also be used for the preparation of reference compoundsfor compounding experiments,to confirm the day-to-dayreliability of testing operations used in the rubber industry,forthe evaluation of experimental compounds,and for qualitycontrol of production compounds.6.Standard Test Formula6.1 The standard formula in Table 1 has been formulated fora silica with a CTAB surface area of 160 m2/g using TESPDsilane,and for a S-SBR 2548 oil extended with 37.5 phrTDAE.If different silica grades or silane types are used,adjustments of the recipe might be required.6.2 NR is needed to increase mixing efficiency for thisformula.Both Standard Malaysian Rubber grade L(SMR L)and Standard Thai Rubber grade L(STR L)are recommendedto give satisfactory performance.Other sources of rubbershould be previously checked to ensure that results are equiva-lent.1This practice is under the jurisdiction ofASTM Committee D11 on Rubber andRubber-like Materials and is the direct responsibility of Subcommittee D11.20 onCompounding Materials and Procedures.Current edition approved Oct.1,2022.Published October 2022.Originallyapproved in 2022.Last previous edition approved in 2022 as D8471 22.DOI:10.1520/D8471-22A.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.16.3 The use of Industry Reference Materials(IRM)asspecified in Specification D5900 is recommended for standardrubber test formulas.37.Mixing Procedure7.1 The mixing procedure for a Standard Internal Mixeraccording to Practice D3182 is describe