简介：Theconformationalanddynamicpropertiesofpolypropylene(PP)forbothpuremeltsandblendswithdifferentchaintacticitywereinvestigatedbyMonteCarlosimulationofisotactic(iPP),atactic(aPP)andsyndiotactic(sPP)polypropylenes.Thesimulationofcoarse-grainedPPmodelswasperformedonahighcoordinationlatticeincorporatingshort-andlong-rangeintramolecularinteractionsfromtherotationalisomericstate(RIS)modelandLennard-Jones(LJ)potentialfunctionofpropanepairs,respectively.ThedynamicsofchainsinbinaryPP/PPmixturewereinvestigatedwiththecompositionofC150H302withdifferentchaintaciticity.ThediffusionratesofPPwithdifferentstereochemistryaregenerallyintheorderas:iPP>aPP>>sPP.ForPP/PPblendswith50:50wt%binarymixtures,immiscibilitywasobservedwhensPPwasintroducedintothemixtures.ThediffusionrateofiPPandaPPbecamesloweraftermixing,whilesPPdiffusessignificantlyfasterinthebinarymixtures.ThemobilityofPPchainsdependsonbothintramolecular(molecularsizeandchainstiffness)andintermolecular(chainpacking)interactions.TheeffectofintramolecularcontributionisgreaterthanthatofintermolecularcontributionforiPPandaPPchainsinbinarymixtures.ForsPPchain,intermolecularinteractionhasgreaterinfluenceonthedynamicsthanintramolecularcontribution.

简介：Inordertoimprovetheflexibilityofpoly(propylenecarbonate)(PPC),poly(1,2-propylenesuccinate)(PPSu)wasusedtoplasticizePPCinabatchmixer.TheeffectsofPPSuonthemiscibility,thermalstability,mechanicalandrheologicalpropertiesoftheblendswereinvestigated.PPCwaspartiallymisciblewithPPSu.ItwasdemonstratedthatPPSudecreasedtheglasstransitiontemperatureandmeltviscosityofPPC,asshownintheDSCandrheologicalcurves.WiththeincreaseinPPSucontent,thePPC/PPSublendsshoweddecreasedtensilestrength,however,theelongationatbreakwasincreasedto1100%forthe70/30PPC/PPSublend.TheintroductionofPPSuprovidedanefficientandnovelplasticizationmethodtoextendtheapplicationareaofPPC.