elastollan-materia-propertiesl-en

TechnicalInformationThermoplasticPolyurethaneElastomers(TPU)Elastollan®-MaterialPropertiesElastogranisPolyurethanes2ContentsIntroductionChemicalstructurePhysicalpropertiesMechanicalpropertiesThermalpropertiesGaspermeabilityElectricalproperties4566Rigidity7Shorehardness9Glasstransitiontemperature10Torsionmodulus11Tensilestrength14Tearstrength21Creepbehaviour22Compressionset24Impactstrength24Abrasion25Friction2526Thermalexpansion26Thermaldeformation27Vicatsofteningtemperature27Heatdeflectiontemperature28Thermaldata29Maximumservicetemperature303133Tracking33Dielectricstrength33Surfaceresistivity33Volumeresistivity34Dielectricconstant34Dielectriclossfactor343ContentsChemicalpropertiesSwellingChemicalresistanceMicrobiologicalresistanceHydrolysisresistanceRadiationresistanceOzoneresistanceFirebehaviourQualitymanagementIndexofkeyterms353536Acidsandalkalinesolutions36Saturatedhydrocarbons36Aromatichydrocarbons36Lubricatingoilsandgreases37Solvents37383940UV-radiation40Highenergyirradiation40404142434IntroductionElastollanistheregisteredtrademarkofourthermoplasticpolyurethaneelastomers(TPU),whichareavailableinunplasticizedforminahardnessrangefrom60ShoreAto74ShoreD.Thesematerialsaredistinguishedbythefollowingproperties:●highwearandabrasionresistance●hightensilestrengthandoutstandingresistancetotearpropagation●excellentdampingcharacteristics●verygoodlow-temperatureflexibility●highresistancetooils,greases,oxygenandozone.5ChemicalstructureElastollanisessentiallyformedfromtheinter-reactionofthreecompo-nents:1.polyols(long-chaindiols)2.diisocyanates3.short-chaindiolsThepolyolsandtheshort-chaindiolsreactwiththediisocyanatesthroughpolyadditiontoformlinearpolyurethane.Flexiblesegmentsarecreatedbythereactionofthepolyolwiththediisocyanate.Thecombina-tionofdiisocyanatewithshort-chaindiolproducestherigidcomponent(rigidsegment).Fig.1showsindia-grammaticformthechainstructureofthermoplasticpolyurethane.Thepropertiesoftheproductdependonthenatureoftherawmaterials,thereactionconditions,andtheratioofthestartingmaterials.Thepolyolsusedhaveasignificantinfluenceoncertainpropertiesofthethermoplasticpolyurethane.Eitherpolyester-basedpolyols(B,C,S,500and600grades)orpolyether-basedpolyols(1100grades)areusedintheproductionofElastollan.Theproductsaredistinguishedbythefollowingcharacteristicfeatures:Polyesterpolyol:●highestmechanicalproperties●highestheatresistance●highestresistancetomineraloilsPolyetherpolyol:●highesthydrolysisresistance●bestlow-temperatureflexibility●resistancetomicrobiologicaldegradationInadditiontothebasiccomponentsdescribedabove,manyElastollanformulationscontainadditivestofacilitateproductionandprocess-ability.Furtheradditivescanalsobeincludedtomodifyspecificproper-ties.Suchadditivesincludemouldreleaseagents,flameretardants,UV-stabi-lizersandplasticizersforflexiblegrades.Glassfibresareusedtoincreaserigidity(RTPU,ElastollanRgrades).StructureofthermoplasticPolyurethaneFig.1FlexiblesegmentFlexiblesegmentRigidsegmentRigidsegment=Residueoflong-chaindiol(ether/ester)=Residueofshort-chaindiol=Residueofdiisocyanate=Urethanegroup6PhysicalpropertiesMechanicalpropertiesThephysicalpropertiesofElastollanarediscussedbelow.Thetestproceduresareexplainedinsomedetail.TypicalvaluesofthesetestsarepresentedinourTechnicalInformation”Elastollan–ProductRange“andinseparatedatasheets.Testsarecarriedoutoninjectionmouldedsamplesusinggranulatewhichispre-driedpriortoprocess-ing.Beforetestingspecimensareconditionedfor20hoursat100°Candthenstoredforatleast24hoursat23°Cand50%relativehumidity.Thevaluesthusobtainedcannotalwaysbedirectlyrelatedtothepropertiesoffinishedparts.Thefollowingfactorsaffectthephysicalpropertiestovaryingdegrees:●partdesign●processingconditions●orientationofmacromoleculesandfillers●internalstresses●moisture●annealingConsequently,finishedpartsshouldbetestedinrelationtotheirintendedapplication.7PhysicalpropertiesMechanicalpropertiesTheversatilityofpolyurethanechemistrymakesitpossibletopro-duceElastollanoverawiderangeofrigidity.Fig.2showstherangeofE-modulusofTPUandRTPUincomparisontoothermaterials.Themodulusofelasticity(E-modulus)isdeterminedbytensiletestingaccordingtoDINENISO527-2atastrainrateof1mm/min,usingatypeAtestspeci-menaccordingtoDINENISO3167.TheE-modulusiscalculatedfromtheinitialslopeofthestress-straincurveasratioofstresstostrain.Itisknownthatthemodulusofelas-ticityofplasticsisinfluencedbythefollowingparameters:●temperature●moisturecontent●orientationofmacromoleculesandfillers●rateanddurationofstress●geometryoftestspecimens●typeoftestequipmentFigs.3–5showthemodulusofelasticityofseveralElastollangradesasafunctionoftemperature.E-modulusvaluesobtainedfromthetensiletestarepreferabletothosefromthebendingtest,sinceinthetensiletestthestressdistributionthroughouttherelevanttestspecimenlengthisconstant.RigidityComparisonofE-modulusofTPUandRTPUwithothermaterialsFig.2E-modulus[MPa]1101001000100001000001000000TPU/RTPUPVCPERubberPCPAABSAlSt8PhysicalpropertiesMechanicalpropertiesRigidity–20–100102030405060708010000100010010Influenceoftemperatureo