简介：Threenewcatalystsbasedonthesilicagelsupportedpolyetherionicliquids(ILs),i.e.,[HO-PECH-MIM]Cl-Si,[H2N-PECH-MIM]Cl-Si,and[HOOC-PECH-MIM]Cl-Si,wereprepared,andtheirchemicalstructureswerecharacterizedbyinfrared(IR)spectroscopyandnuclearmagneticresonance(NMR)spectroscopy.Thermogravimetricanalyzer(TG),X-raydiffractometer(XRD)andscanningelectronmicroscope(SEM)wereusedtoevaluatetheirthermalstability,crystallinestructureandapparentmorphology,respectively.SurfaceareasofthepreparedcatalystswerecalculatedbytheBrunauer-Emmett-Teller(BET)method.Thecatalyticreactionforthesynthesisofpropylenecarbonate(PC)usingCO2andpropyleneoxide(PO)inthepresenceofthepreparedcatalystswasstudied.Theinfluencesoftimesofrecyclingandcatalyststructureoncatalyticperformancewerealsoinvestigated.TheexperimentalresultsshowedthatthesilicagelsupportedpolyetherILscatalystssuccessfullypreparedundermildconditioncouldpossesstheadvantagesofhighactivity,excellentthermalstability,goodselectivityandeasyrecycling,whilethephasetransitionoftheliquidpolyetherILscatalystswasalsoachieved.Whenthereactiontemperaturewas90°C,theCO2pressurewas2.0MPaandthedosageofthecatalystwas2.5%,[HOOC-PECH-MIM]Cl-Siwasfoundtohavethebestcatalyticperformanceinthecatalyticprocess,withtheconversionratereaching100%andtheselectivityequatingto98.2%.Theconversionrateandselectivitystillcouldreachmorethan90%evenafterthecatalystwasreusedfor15times.
简介：Apolymericgelisanaggregateofpolymersandsolventmolecules,whichcanretainitsshapeafteralargedeformation.ThedeformationbehaviorofpolymericgelswasoftendescribedbasedontheFlory-Rehnerfreeenergyfunctionwithoutconsideringtheinfluenceofchainentanglementsonthemechanicalbehaviorofgels.Inthispaper,anewhybridfreeenergyfunctionforgelsisformulatedbycombiningtheEdwards-Vilgisslip-linkmodelandtheFlory-Hugginsmixingmodeltoquantifythetime-dependentconcurrentprocessoflargedeformationandmasstransport.Thefiniteelementmethodisdevelopedtoanalyzeexamplesofswelling-induceddeformation.Simulationresultsarecomparedwithavailableexperimentaldataandshowgoodagreement.Theinfluenceofentanglementsonthetime-dependentdeformationbehaviorofgelsisalsodemonstrated.Thestudyoflargedeformationkineticsofpolymericgelisusefulfordiverseapplications.
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