简介:TiCl_4/MgCl_2/claycompoundcatalystwaspreparedbychemicalreaction.Exfoliatedpolypropylene(PP)/claynanocompositesweresynthesizedbyinsitupolymerizationwiththiscompoundcatalyst.Effectsofpolymerizationtemperature,polymerizationtime,propylenepressure,solventconsumptionandpre-treattimeofcatalystoncatalystactivityandcatalyticstereospecificitywerestudied.Underoptimalconditions,activityofthenano-compoundcatalystisabout88.3kg/(molTi·h).IsotacticityofPPobtainedinthenanocompositesisintherangeof89%-99%,anditsmeltingtemperatureisabout159℃.Theweight-averagemolecularweightofPPcanreach6.7×10~5-7.8×10~5,andthemolecularweightdistributionisbetween7.7and7.9.
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:Gasphasereductionofcarbonmonoxidetoformaldehydeandethylenewasfoundinelectrochemicalcellwithaninorganicionexchangerα-Zr(HPO4)2·H2Ousedassolidproton-conductingelectrolyteatroomtemperatureandatmosphericpressure.ThetypeandamountoftheelectroreductionofCOdependonthedifferentmetalelectrodesandcurrentdensities,whichgivesalankbetweenheterogeneouscatalysisandelectrochemistry.
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:Dithia-monoaza18-Crown-6anditsimmobilizationproduct,silica-bound1,7-dithia-4-aza-10,13,16-trioxa-cyclooctadecaneviaaspacerofthreecarbonatoms,anditsplatinumcomplexhavebeensynthesized.Itisfoundthattheplatinumcomplexisanefficienthydrosilylationcatalystforolefins.TheXPSdataoftheplatinumcomplexarereported.
简介:Newmodelcompound1H,1′H-Bis(benz-Δ^4-imidazoline)2,2′-spiro-titaniumdichloridewaspreparedandthestructureofthecompoundwasdeterminedby1R,MSandelementaryanalysis.
简介:Linearpolysiloxaneswithpendantbenzo-15-crown-5moietieshavebeensynthesizedfrom3′-or4′-allylbenzo-15-C-5viahydrosilylationofmethyldichlorosilane,followedbypolycondensationwithsilanol-terminatedpolydimethylsiloxane.Itwasfoundthatthepolysiloxanescouldbeusedascarriersinbulkliquidmembranetotransportions.Factorsinfluencingtransportratehavebeeninvestigated.
简介:Ourobjectivesweretodevelopanewchemicalmethodforthepolymerizationofpyrrole.CuCl2dissolvedinC2H5OHsolventisprimarilyusedfortheinitiationpolymerizationofpyrrole.ThepolymerswithdifferentyieldandconductivitywereobtainedbyraringtheinitialconcentrationofCu2+.TheinitialconcentrationsofCu2+variedfrom1.2×10-4moleto6.48×10-3moleCu2+with2.16×10-2molepyrrole.Thepolypyrroleobtainedwascharacterizedwithelementalanalyzer,XPS,IRspectroscopy,Four-pointprobeandSEM.
简介:Inthispaperstudyonthepropertyandmechanismofadsorptingrheniumfromaqueoushydrochloricacidbyusingmethylphosphorousaciddimythylheptylesterlevextrelresin(CL-P350)isreported.Theeffectsoftime,acidity,concentrationofrhenium,andtemperatureontheadsorptionofrheniumwereinvestigated.ThemechanismofadsorptingrheniumwasdiscussedbychemicalanalyticandIRmethod,anddynamicadscrptionandelutionwerestudied.Experimentalresultsshowthattheadsorptionequilibrationisreachedin4min,thedistributioncoefficient(D)ofRe(Ⅶ)increaseswithincreaseofconcentrationofHClandreachesmaximum3.0-4.0moL/LHCl.ReO4^-istakenupbyionassociationmechanismandcanbedescribedbyLangmuirequationoftheequilibriumstate.ThethermodynamicparametersintheadsorptionprocessofReO4^-havebeendeterminedtobe:ΔH=-29KJ/moL,ΔG=-25KJ/moLandΔS=-13.5J/moLrespectively.Thesaturationadsorptioncapacityofrheniumis19.2mg/gwhenthesolutioncontaining0.372g/LReand3.0mol/LHClwaspassedthroughtheresincolumn.Therecoverypercentageofrheniumis98.4%whiledistilledwaterwasusedasaneluent.
简介:Opticallyactive(R)-(+)-2,2’-bis(2-trifluoro-4-aminophenoxy)-1,1’-binaphthylwaspreparedfrom1,1’-bi-2-naphthol.Theopticallyactivearomaticpolyimidewasalsosuccessfullysynthesized.Thisnewpolymerhasgoodsolubility,thermalstabilityetc.Itsspecificrotationwasfoundtobe+174°,anditschiropticalpropertywasalsostudied.
简介:在这个工作,综合体新热地稳定(amide-imide)poly,有在n丁基甲基imidazolium溴化物的悬挂的2-pyridyl-1,3,4-oxadiazole单位的s作为反应媒介被报导了。新二羟基的酸从肼的反应被导出,2-(5-(3,5-diaminophenyl)-1,3,4-oxadiazole-2-yl)pyridine(POBD),和trimellitic酸酐。聚合物在丁基甲基imidazolium溴化物从diimide二酸(DIDA)和不同的芳香的肼的反应被准备,[bmim][Br],面对triphenyl亚磷酸盐(TPP)作为没有需要任何额外的部件的压缩代理人。poly准备了(amide-imide)s被FTIR描绘,元素的分析,并且通过模型混合物的合成。准备聚合物是可溶的在极并且aprotic溶剂例如DMF,DMSO,NMP和DMAc。聚合物答案的固有的粘性在在0.125g/dL的集中在集中的H2SO4测量在的0.521.33dL/g的范围(25