Characterization of mono-ethylene-glycol based industrial polyurethanes samples by fast-neutron radiography and neutron tomography

摘要

Acomplicatedstructuralorganizationofpolyurethanesmayhaveastronginfluenceonthematerialsfunctionalproperties.Underparticularconditionssuchasmechanicalandthermalloadingandaging,itleadstothematerialdegradation,eveninfresh-preparedbulkpolymersandespeciallyifdefectsarepresentinthematerial.Unwantedbubblescanbeobserved,whichformduringtheexpansionofthemixtureduringitschemicalreactionandremainpresentinthefinalproduct.Thesemacro-,micro-andnano-bubblesinfluencethematerial'sperformance.Inthiswork,neutronradiographyandtomographyhavebeenadoptedtocharacterizeatamacro-scalelevelthebulkofcommerciallyavailablepolyurethanesamples,obtainedfromdissimilar-mixtureratioswithdifferentdensitiesandbranchinglevelsaswellasfromdifferentzonesoftheproductionmould.Thecharacterisationallowedanestimationofthedifferentdensematerials-astheyareused,e.g.,insolesofshoes-aswellastheinvisibledefectslikeporesandcracks,responsibleforthematerialsfracturebymechanicalloading.Theobtainedinformationareexpectedtobeusefulforvariousindustrialsectorssuchasautomotiveandfootwearindustry.ItwillbecompletedbyapplyingSANS,whichhasalreadyprovedtocharacterizethemicrostructureofthebulk-polymerwithrespecttonano-pores,micro-cracksandtheirarrangementinthepolymermatrix...