简介:TheNdCl3/MgCl2bisupportedcatalystwaspreparedbyusingNdCl3,MgCl2,(CH3)2(CH2)2OHandTiCl4.ItisshownthatthestructureofbisupportedcatalystwasdifferentfromthoseofeitherNdCl3orMgCl2singlesupportedcatalyst.Apeculiartypeofkineticcurveforethylenepolymerizationwasfound.
简介:为综合的一条non-isocyanate线路有优秀热、机械的性质的热塑的聚氨酯被描述。与四个聚乙烯乙二醇木钉融化1,6-bishydroxyethyloxy羰基aminohexane的transurethanepolycondensation,即PEG400,PEG600,PEG1000,或PEG1500,在不同臼齿的比率被进行。有长木钉序列的一系列热塑的polyetherurethanesTPEU被准备。TPEU经由胶化浸透层析被描绘,FTIR,<啜class=“a-plus-plus”>1H-NMR,微分扫描热量测定,thermogravimetric分析,散布的宽角度的X光检查,和张力的测试。TPEU展览T<潜水艇class=“a-plus-plus”>在12.4汦灡之间的g?
简介:Polyolefinsthatbearachiralsidechain(typicallyanisobutylgroup)experienceaso-calledmacromolecularamplificationofchirality:thechiralside-chaininducesaslightpreferenceforeithertgortg-mainchainconformation.Thisslightconformationalbiasisamplifiedcooperativelyalongthechain,andresultsinpreferredchiralityofthemainchainhelicalconformations.Asaresult,thesepolymersdisplayaliquid-crystal(LC)phasebothinsolutionand,inthemeltasatransientphaseonthewaytocrystallization.Theexistenceoftwoprocesses(melt-LCandLC-crystaltransitions)resultsinunconventionalbehaviorsthatwerefirstanalyzedbyPinoandcollaboratorsbackin1975.Thesepolymersalsoofferameanstotestthestructuralconsequencesofrecentlyintroducedcrystallizationschemes.Theseschemespostulatetheformationofatransientliquid-crystalphaseasageneralschemeforpolymercrystallization.
简介:Conventionalchloromethylation,paraformaldehyde/hydrogenchlorideinaceticacidmedium,wasappliedto1,2-dimethoxybenzene.Chloroform-solublepoly(3,4-dimethoxy-o-tolylene)wasobtainedwithanintrinsicviscosityof0.034dLg~(-1).ThepolymerwasevaluatedasacondensationredoxpolymerprecursorformedbyaFriedel-Craftsreaction.Cleavageofthemethoxygroupspresentinthispolymerresultedinpoly(3,4-dihydroxy-o-tolylene)whichmanifestedagreatair-oxidationresistance.Theredoxpropertyofthelatterpolymerwasfoundtobe1017mVbypotentiometrictitrationwith0.05Ncericammoniumnitrateat25℃.Thismidpotentialwascomparedtothatofcatechol,amonomericanalogue,underthesametitrationconditions.
简介:TheconductivitybehaviorofAl(OH)3-acrylamidehybridpolyacrylamide(hybridPAAm)indistilledwaterwasstudied.Adiscontinuityphenomenonoftheconductivity(k)versusconcentration(c)curveofthehybridPAAminacertainconcentrationregimeisfound.ThisphenomenonisdependentonthemolecularweightofthehybridPAAmandontheparticlesizeandcontentoftheAl(OH)3colloidinthehybridPAAm.ThisphenomenonwasaccountedforassumingionizationofthehybridPAAm.
简介:TheeffectsofHDPEmatrixtoughnessonthebrittle-ductiletransitionofHDPE/CaCO3blendsareinvestigated.NotallHDPEcanbetoughenedbyCaCO3particles.TheabilityofthematrixtoyieldplaysafundamentalroleindetermingwhetherHDPEcanbetoughenedornot.Thereexistsacriticalmatrixtoughness(Isc≈45J/m)belowwhichHDPEcannotbetoughenedobservablybyCaCO3particleatgivenaveragesize,andabovewhichthecriticalmatrixligamentthickness(τ?)isproportionaltomatriximpactstrength.
简介:Thechemicalgraftingofthiolterminatedpoly(sodiumstyrenesulfonate)(HS-PSSS)chainsfromsodiumnitrate(NaNO3)saltsolutiontoagoldsurfacewasinvestigatedwithaquartzcrystalmicrobalancewithdissipationmonitoring(QCM-D)indifferentsaltconcentrations.ItwasfoundthatatlowsaltconcentrationgraftingdensityofHS-PSSSwaslowandthegraftedchainsadoptedamushroomconformation.Withtheincreaseofsaltconcentrationpolyelectrolytechainsunderwentatransitiontowardcoiledstateduetoreductionofelectrostaticrepulsionandasaresultmorechainsweregraftedonthesurface.WhenthegraftingdensityreachedacertainlimitafterwhichfurthergraftingcausedrepulsionbetweenalreadygraftedHS-PSSSchainsandasaresultgraftedchainsadoptedabrushconformation.
简介:OrganicchelatingreagentinfluencesupontheredoxadsorptionofactivatedcarbonfibertowardsAu3-weresystematicallyinvestigated.TheexperimentalresultsindicatedthatthepresenceoforganicchelatingreagentonactivatedcarbonfiberstronglyaffectsadsorptioncapacityofactivatedcarbonfibertowardsAu3+.Thereduction-adsorptionamountofAu3+increasedthreetimesbythepresenceof8-quinolinol.Furthermore,Thereduction-adsorptionamountofAu3+dependedonthepHvalueofadsorptionandtemperature.
简介:Solublepoly(3-hexyl-2,5-thienylenevinylene)(PHTV)wasreadilysynthesizedfromthiopheneinayieldbetterthanthatoftheprecursormethodtopreparepoly(thienylenevinylene)(PTV).Thebandgapofthepolymerisabout1.8eV,whichiscomparablewiththatofPTV.Owingtotheintroductionofalkylsidegroupsontothebackboneofthepolymer,itcanbedissolvedincommonorganicsolventssuchaschloroform,THFandtoluene.ThesynthesisofsolublePHTVisaveryimportantapproachtopreventingoxidationandtoimprovingthepropertiesandtheprocessbilityofthePTV.TheexistenceofalkylsidegroupsinPHTVdoesnotaffectits,bandgapandthermalpropertiesascomparedwithPTV.AfterdopingwithFeCl3,theconductivityofPHTVisashighas1.1×10-2S/cm.ThesolublePHTVcanbeeasilytransformedintothinfilmwithmuchbetterqualitythanthatofthePTVfilmpreparedbythetraditionalprecursormethod,whichisveryimportantforfabricatingdeviceswithgoodproperties.
简介:CuO/γ-Al2O3catalystswerepreparedbyplasmatreatmentandconventionalimpregnationmethods.Thecatalyticcombustionoftwokindsofvolatileorganiccompounds(VOCs),tolueneandbenzene,werecarriedoutovertheseCuO/γ-Al2O3catalysts.ThesurfacepropertiesofthesecatalystswerecharacterizedbyX-rayDiffraction(XRD)andScanningElectronMicroscopy(SEM).TheexperimentalresultsshowedthatincatalyticcombustiontheactivityoftheCuO/γ-Al2O3catalystpreparedviaplasmawasmuchhigherthanthatoftheCuO/γ-Al2O3catalystpreparedbyconventionalimpregnationmethod.XRDresultsshowedthatanenhanceddispersionhadbeenachievedwiththeplasmatreatment.SEMresultsindicatedthatthesizebecamemuchsmallerandthesurfacebecamemoreuniformwiththeplasmatreatment.
简介:Acylationreactionofanthracenewithoxalylchlorideinthepresenceof[Emim]C1-A1C13ionicliquidhasbeeninvestigated.Pure1,2-aceanthryenedione,whichisusedasintermediateoffunctionalaromaticpolymermaterial,wasobtainedbyrecrystallingthereactionmixturewithaetherandwasdeterminedbyGC/MS,1HNMRandFTIRanalysis.Theinfluencesofvariousparameters,suchasthecontentsofAlCl3in[Emim]C1-A1C13,theamountofacylationagent,amountof[Emim]C1-A1C13,reactiontemperatureandreactiontimewereinvestigated.Theoptimumconditionswereasfollows:themolarfractionofA1C13inionicliquid[x(AlCl3)]being0.67,molarratioofionicliquidtoanthracenebeing2:1,molarratioofoxalylchloridetoanthracenebeing2:1,reactiontemperaturebeing40℃andreactiontimebeing6h.Underaboveconditions,theyieldandselectivityof1,2-aceanthrylenedionecanreach91.5%and98.3%respectively.Furthermore,[Emim]C1-A1C13ionicliquid,comparedwithmetalhalidessuchasAlCl3,wasfoundtocatalyzethereactionasanovelenvironmentalfriendlycatalystandsolventandcanbereused.
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简介:Immobilizedtriazinedyeaffinitychromatographyhasbeenwidelyusedforproteinpurification.Inthispaper,CibacronBlueF3G-4wasimmobilized,throughaspacerarm,ontoarigidhydroplhilicporouspolymerbyreactinganepoxy-group-containingpoly(vinylalcohol)with6-aminohexyl-N'-CibacronBlueF3G-A,whichwasobtainedbyreactingCibacronBlueF3G-4withexcessof1,6-diaminohexane,inapH8.6buffer,Theepoxy-group-containingpoly(vinylalcohol)waspreparedbytreatingmacroporouspoly(vinylalcohol)withexcessepichlorohydrininthepresenceofNaOHindimethylsulfoxide.Themacroporouspoly(vinylalcohol)waspreparedbyhydrolysisofmacroporouscrosslinkedpoly(vinylacetate),whichwassynthesizedbysuspensioncopolymerizationofvinylacetateandtriallylisocyanurateinthepresenceofbutylacetateandn-heptaneasdiluents.TheCibacronBlueF3G-A-immobilizedpoly(vinylalcohol)waspackedinastainlesssteelcolumn(250×5mmI.D.)andthechromatographicbehaviorsofseveralproteins(cytochromec,lysozyme,bovineserumalbumin,insulin,andlactatedehydrogenase)weredetermined.
简介:Amovingboundarymodelunderconsideringthevolumechangeofsphericalresinbeadsduringionexchangeprocesseswasemployedtorecognizethemechanismsofreecoveringuraniumfromcarbonatesolutionsusingstronglybasicanionexchanger.Twoimportantfactors,swellingandionexchange,whichdirectlyaffecttheviolumeofionexchangersweretakenintoaccount.AnionexchangemechanismhasbeenfoundfortheforwardreactionPCl/[UO2(CO3)3]^4-,andisparticaldiffusiongoverningathighconcentrationofthecomplexanion.ThemechanismofRCl/U(VI)atpH5.5-7.5isachemicalreactiontakingplaceatthemovingboundaryoftheunreactednucleus.ForthereversereactionRnU/NaCl,theuranyltricarbonatecomplexanionintheresinphaseisreplacedbyCl^-ionswithanionexchangemechanismalwaydeterminedbyparticlediffusion.TheotherformsofuraniuminthesolidphaseloadedontheresinatpH5.5-7.5shouldbelongtonon-exchangeableuranium.ThemechanismofthereversereactionRnU/HClisalwayschemicalreactionwhichisnotrestrictedtothemovingboundaryoftheunreactedcore.
简介:Asidechainliquidcrystallinecopolysiloxane,whichwouldshowelectro-opticeffectsasknownfromlowmassliquidcrystal,wassynthesizedbyhydrosilylationreaction,andthetwohomologousmonomerswithdifferentlengthspacerscontainingSchiff’sbasemesogenwith—NO2terminatedgroupweregraftedtoapolysiloxanemainchain.Residualmonomerincrudeproductiseffectiveinreinforcingtheresponsetoanelectricfieldoverthatofpurepolymericliquidcrystal.
简介:Kineticsofchloride/sulfate,chloride/nitrateandnitrate/sulfateforwardexchangesandreverseexchangesatsolutionconcentrationsof1N,0.2Nand0.02Non201×7strongbaseanionexchangeresin,respectively,havebeenexaminedat25℃.Itisfoundthattheforwardandthereverseexchangeratesofthetwogivenionsatlowsolutionconcentration,respectively,underidenticalconditionscanbecontrolledbydifferentmechanisms,whilethoseathighsolutionconcentrationareallcontrolledbyparticlediffusion.Theternaryexchangeratesofsulfate/(chloride+nitrate)andnitrate/(chloride+sulfate)havealsobeenexamined.
简介:Theadsorptionbehaviorofionicgoldontochelatingfibercontainingamidoximegroupswasinvestigated.ThechelatingfiberpresentshighadsorptioncapacityforionicgoldAu^3+(upto626mg/g,whenthecontentofamidoximegroupreaches7.59mmol/g),andpossessestheabilitytoreducetheAu^3+intometallicgold,Intheredoxprocess,theamidoximegroupisoxidizedintocarboxylgroup.