ASTM_D_5775_-_95_2019.pdf

Designation:D577595(Reapproved 2019)Standard Test Method forRubberDetermination of Bound Styrene in StyreneButadiene Rubber by Refractive Index1This standard is issued under the fixed designation D5775;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 test method covers the determination of styrenecontent,and is intended for general use on solid uncom-pounded styrene-butadiene copolymers,commonly referred toas SBR,prepared by the emulsion process.SBR polymersprepared in solution will require the use of different refractiveindex tables because the vinyl content of the butadiene differsfrom that in the emulsion polymers.It is applicable to polymershaving less than 55%bound styrene.NOTE1The nomenclature used in this test method is in accordancewith Practice D1418.1.2 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.3 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:2D1418 PracticeforRubberandRubberLaticesNomenclatureD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries3.Summary of Test Method3.1 A sample of dried ETA-extracted polymer is pressedbetween sheets of aluminum foil to provide sheeted rubberhaving a thickness of not more than 0.50 mm.The boundstyrene content is calculated from the refractive index obtainedat 25C on this thinly sheeted rubber.4.Significance and Use4.1 The bound styrene test is a measure of the boundmonomeric composition of the rubber.It is used as a check onthe accuracy of monomer charging and also as a guide to theuniformity of the product,since the bound styrene contentaffects the physical properties.5.Apparatus5.1 Spiders,consisting of 13-mm squares of sheet alumi-num or stainless steel having a Nichrome wire leg about 38 mmlong attached to each corner.Where the extracting solvent isETA-acidified with HCl,the spider and the legs should bemade of tantalum.5.2 Abbe-Type Refractometer,having fourth decimal placeaccuracy,whose refracting prism can be placed in a nearlyhorizontal position for measurement of the refractive index ofsolids.AnAmici-type compensating prism for achromatizationis necessary unless a sodium vapor lamp is used as a lightsource.5.3 Vacuum Oven,capable of being evacuated to a pressureof 1.3 kPa(10 mm Hg)and of maintaining a temperature of100C.5.4 Aluminum Foil,between 0.025 and 0.08 mm thick,having good tear strength.5.5 Glass Test Piece,standard,for checking adjustment ofthe refractometer.5.6 Hydraulic Press,that can be maintained at 100C andcan apply a force of at least 2.2 kN(500 lbf)on each specimenor of 100 kN(11 ton)if pressing plates as described in 5.7 areused.5.7 Pressing Plates(Optional Apparatus),210 by 210 by 3mm,with a wooden handle.One of the plates should have a1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand Rubber-like Materials and is the direct responsibility of Subcommittee D11.11on Chemical Analysis.Current edition approved Jan.1,2019.Published February 2019.Originallyapproved in 1995.Last previous edition approved in 2014 as D5775 95(2014).DOI:10.1520/D5775-95R19.2For 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.1 150-mm square area in the center of the plate milled out to adepth not to exceed 0.65 mm.5.8 Scissors,small and sharp.5.9 Light SourceThe light source should be collimated toprovide a beam at grazing incidence to the prism.If anincandescent light source is used,it shall be of low intensity,such as a flashlight bulb.A sodium vapor lamp may also beused.The light source requirement is that a clear sharp linewith good contrast can be observed in the tel