Designation:D5775−95(Reapproved2014)StandardTestMethodforRubber—DeterminationofBoundStyreneinStyreneButadieneRubberbyRefractiveIndex1ThisstandardisissuedunderthefixeddesignationD5775;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofstyrenecontent,andisintendedforgeneraluseonsoliduncom-poundedstyrene-butadienecopolymers,commonlyreferredtoasSBR,preparedbytheemulsionprocess.SBRpolymerspreparedinsolutionwillrequiretheuseofdifferentrefractiveindextablesbecausethevinylcontentofthebutadienediffersfromthatintheemulsionpolymers.Itisapplicabletopolymershavinglessthan55%boundstyrene.NOTE1—ThenomenclatureusedinthistestmethodisinaccordancewithPracticeD1418.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1418PracticeforRubberandRubberLatices—NomenclatureD4483PracticeforEvaluatingPrecisionforTestMethodStandardsintheRubberandCarbonBlackManufacturingIndustries3.SummaryofTestMethod3.1AsampleofdriedETA-extractedpolymerispressedbetweensheetsofaluminumfoiltoprovidesheetedrubberhavingathicknessofnotmorethan0.50mm.Theboundstyrenecontentiscalculatedfromtherefractiveindexobtainedat25°Conthisthinlysheetedrubber.4.SignificanceandUse4.1Theboundstyrenetestisameasureoftheboundmonomericcompositionoftherubber.Itisusedasacheckontheaccuracyofmonomerchargingandalsoasaguidetotheuniformityoftheproduct,sincetheboundstyrenecontentaffectsthephysicalproperties.5.Apparatus5.1Spiders,consistingof13-mmsquaresofsheetalumi-numorstainlesssteelhavingaNichromewirelegabout38mmlongattachedtoeachcorner.Wheretheextractingsolventi...
