Designation:D2857−95(Reapproved2007)StandardPracticeforDiluteSolutionViscosityofPolymers1ThisstandardisissuedunderthefixeddesignationD2857;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoversthedeterminationofthedilutesolutionviscosityofpolymers.ThereareseveralASTMstandards(TestMethodsD789,D1243,D1601,andD4603,andPracticeD3591)thatdescribedilutesolutionviscosityproceduresforspecificpolymers,suchasnylon,poly(vinylchloride),polyethylene,andpoly(ethyleneterephthalate).Thispracticeiswrittentoaugmentthesestandardswhenproblemsarisewithwhichthespecificprocedureisnotconcerned,orwhennostandardisavailableforthepolymerunderinvesti-gation.1.2Thispracticeisapplicabletoallpolymersthatdissolvecompletelywithoutchemicalreactionordegradationtoformsolutionsthatarestablewithtimeatatemperaturebetweenambientand150°C.Resultsareusuallyexpressedasrelativeviscosity(viscosityratio),inherentviscosity(logarithmicvis-cositynumber),orintrinsicviscosity(limitingviscositynum-ber)(see3.1).1.3Forpolyamides,relativeviscosityvaluesbythisproce-durearenotequivalenttothosedeterminedbyTestMethodsD789.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.NOTE1—ThisstandardandISO1628,“Plastics—DeterminationofViscosityNumberandLimitingViscosityNumber,”aretechnicallyequivalent.2.ReferencedDocuments2.1ASTMStandards:2D445TestMethodforKinematicViscosityofTransparentandOpaqueLiquids(andCalculationofDynamicViscos-ity)D446SpecificationsandOperatingInstructionsforGlassCapillaryKinematicViscometersD789TestMethodsforDeterminationofSolutionViscosi-tiesofPolyamide(PA)D883TerminologyRelatingtoPlastic...
