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Inpresentwork,westudiedtheshapememoryperformancesofbio-basedpolyester(BE)compositeswhichwerereinforcedbythreekindsofnanofillers(boehmite(BM),vaporgrowncarbonnanofiber(VGCF),andVGCF-graphenehybrid).BEwassynthesizedthroughpolycondensationusingtheplant-derivedresourcesasthestartingmaterials.WiththeincorporationofnanofillersintoBE,theBEcompositesweresignificantlyreinforced,meanwhile,fasterbiodegradationrate,electro-activation,andinfrared-actuationpropertiesofthecompositesimpartedbynanofillerswereinvestigated.IntheBE/BMcomposites,strongerandfasterdegradableshapememorypolymers(SMPs)werepreparedwiththeincorporationofBMintoBE.ByvaryingtheBMcontentandcuringagentcontent,thetransformationtemperatureofSMPscompositescouldbetunedtobeclosetobodytemperature.TheinteractionsbetweenBMandBEchain,whichwereessentialforthecompatibilitybetweenthem,werecharacterizedindetail.Thepotentialbiocompatibility,assubstantiatedbytheoutstandingcellviabilityandcellattachment,togetherwiththerealizationoftransformationtemperatureclosetobodytemperaturemaketheBE/BMcompositessuitableforthebiomedicalapplications,suchasstents,inhumanbody.VGCFwereincorporatedintoBEtoprepareBE/VGCFcompositesbysimplemeltingblending.TheuniformdispersionofVGCFandfairlystronginterfacialadhesionbetweenBEandVGCFledtoasignificantimprovementinthemechanicalpropertiesofthecomposites.Besides,theincorporationofVGCFsuccessfullyconvertedtheinsulatingBEintoelectricallyconductivecompositeswithapercolationthresholdof2.5vol%.Thecompositesshowedexcellent，electroactiveshapememoryproperties,whichreachedashaperecoveryratioof97%within90swithadirectcurrentvoltageof20V.VGCF-graphene(VGCF-G)hybridwaspreparedbydirectlyreducinggrapheneoxideintographeneinNMPwiththeassisted-dispersionofVGCF,producingahomogeneousdispersionofVGCF-Ghybrid.OnedimensionalVGCFwereadsorbedontographenesheetsthrough7r-7rinteractionandtherebypreventedtheaggregationandstackingofthegraphene.TheresultingVGCF-GhybridwasthenincorporatedintoBEthroughsolventmixtureinNMP.Forcomparison,BE/VGCFcompositescontainingVGCFalonewerealsopreparedthroughsolventmixture.ThedispersionofVGCFinthecompositesweregreatlyimprovedandtheinterfacialadhesionbetweenBEandVGCFweresignificantlyenhancedwiththeincorporationofgraphenesheetsascompatibilizer.ComparedwiththeBE/VGCFcompositescontainingVGCFalone,aremarkablesynergeticeffectsbetweenVGCFandgrapheneinimprovingtheelectricalconductivityandmechanicalpropertieswereobservedintheBE/VGCF-Gcomposites.Furthermore,themulti-stimuliresponsive(electro-activatedandinfrared-triggered)shapememoryperformancesofthecompositesareinvestigated.Atfixedfillercontent,theBE/VGCF-Gcompositesshowedthecombinationofhighershapememoryrecovery,strongerstressrecoveryandfasterresponsecomparedwiththeircounterpartscontainingVGCFalone. |
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