简介:Theadsorptionprocessesofantibioticsofthetetracylinegroup(ATG)byseveralhome-madesulfocationitesarestudiedinthispaper.TheresultsshowthattheadsorptionmaybeofnonequivalentnormalityundercertainpHcondition.Theadsorptionmechanismisdiscussedwithinfraredspectrometry.ItcanbeconcludedthatATGcaninteractwithsulfocationitesbyionexchangemechanismorion-transfermechanismorbothofthem.
简介:Thetitlepolymerwaspreparedfrom5-diethylamino-3-thia-pentylglycidyletheranddiethyleneglycolbisglycidyletherviaring-openingcopolymerization.Itwasfoundthatthisreactioncouldbecatalyzedbysodium,butnotLewisacid.Theobtainedpolymercancoordinatewithplatinumcompound,andtheplatinumcomplexisanewkindofcatalystforthehydrosilylationofolefinswithtriethoxysilane.
简介:Thispaperreportsthekineticsofgrouptransferpolymerization(GTP)ofethylacrylate(EA)withzinciodidecatalystin1,2-dichloroethaneusingdimethylketenemethyltrimethylsilylacetal(MTS)asinitiatorat0℃andabove0℃.Theamountofcatalystusedwasstudied.Whenzinciodidecatalystusedismorethan10mol%relativetomonomer,therateofpolymerizationisproportionaltotheconcentrationofmonomer,whereaszinciodidecatalystusedislessthan10mol%ofthemonomer,therateofpolymerizationisindependentofthemonomerconcentration.IntheGTPofEAaninductionperiodwasobservedwhenthezinciodidecontentsarelessthanl0mol%.Ifthereactiontemperatureisover0℃,livingspeciesbecomeunstableanddiminish,leadingtoincompletemonomerconversion.Thereactioncurvesequationsareobtained.Thepolymershavenarrowmolecularweightdistributionswhicharenotchangedasdecreasingzinciodidecontents.Thepolydispersityisabout1.2.
简介:Thiscontributionreportsethylenepolymerizationbehavioroftitaniumcomplexesincorporatingbis(phenoxyimine)ligands.Sixphenoxy-imineTi(IV)complexes{6-R1-2-[CH=N(2,6-difluoro-3,5-diR2-4-R3Ph)]C6H3O}2TiCl2(1:R1=H,R2=H,R3=H;2:R1=H,R2=H,R3=4-vinylphenyl;3:R1=CH3,R2=H,R3=H;4:R1=CH3,R2=H,R3=4-vinylphenyl;5:R1=CH3,R2=F,R3=H;6:R1=CH3,R2=F,R3=4-vinylphenyl)havebeensynthesizedandevaluatedforethylenepolymerizationusingdriedMAO(simplifiedasDMAO)ascocatalyst.AnobviouscatalyticheterogeneityofCat2(Complex2/DMAO)towardsethylenepolymerizationwasobserved,whichwasillustratedbydecreasedactivity,multimodalmolecularweightdistributionandpartiallyimprovedparticlemorphologycomparingwithCat1.Moreover,Cat3exhibits'living'characteristicsintheprocessundercertainconditions(25°C,lessthan20min).Otherwise,themoderatetohighethylenepolymerizationactivityofca.105-106gPE/(molTi·h)andhighmolecularweight(Mw=105-106)ofpolyethylenecanbeobtainedbychangingtheskeletonstructureofthesecomplexes.
简介:Monodispersecrosslinkedpoly(chloromethylstyrene-co-divinylbenzene)(poly(CMSt-co-DVB))microsphereswerepreparedbydistillation-precipitationcopolymerizationofchloromethylstyrene(CMSt)anddivinylbenzene(DVB)inneatacetonitrile.Thepolymerparticleshadcleansurfacesduetotheabsenceofanyaddedstabilizer.Thesizeoftheparticlesrangesfrom2.59μmto3.19μmandwithmono-dispersityaround1.002-1.014.Theeffectsofmonomerfeedincopolymerizationonthemicrosphereformationweredescribed.ThepolymermicrosphereswerecharacterizedbySEMandchlorinityelementalanalysis.
简介:Acomparisonoftheadsorptionofbenzoicacidandp-nitrobenzoicacidonthenewhypercrosslinkedpolymericadsorbentAM-I,withthatbymacroporousAmberliteXAD-4,includingtheequilibriumadsorptionisotherms,thedynamicadsorptionbehaviorsthroughcolumnandtheadsorptionthermodynamicswerestudied.ResultsshowthatFreundlichequationgivesafittingadsorptionisotherm.ThespecificsurfaceofAM-lisonly67%ofthatofAmberliteXAD-4,buttheadsorptioncapacitiesonAM-1aremuchhigherabout125%~166%thanthatonAmberliteXAD-4,whichiscontributedtothemicroporemechanismandpolarity.Thenegativevaluesoftheadsorptionenthalpyareindicativeofanexothermicprocess.Enthalpyandfreeenergychangesofadsorptionbothmanifestaphysic-sorptionprocess.Thenegativevaluesoftheadsorptionentropyindicatethattheadsorptioniswellconsistentwiththerestrictedmobilitiesandtheconfigurationsoftheadsorbedbenzoicacidmoleculesonthesurfaceofstudiedadsorbentswithsuperficialheterogeneity.Bothadsorbentswereusedinmini-columnexperimentsforadsorbingbenzoicacidexpectingtoelucidatethehigherbreakthroughadsorptioncapacityofthenewhypercrosslinkedpolymericadsorbentAM-1ascomparedwiththatofAmberliteXAD-4.
简介:Threenewpolysesquisiloxane-boundplatinumcomplexesweresynthesizedviahydrolysisofN,N-di(β-ethylmercaptoethyl)γ-(triethoxysilyl)propylamineorcohydrolysisofthemonomerwithdodecyltriethoxysilaneorwithphenylpropylthiethoxysilaneandimmobilixationonfumedsilica,followedbyreactingwithpotassiumplatiniteinacetoneunderargonatmosphere.Theplatinumcomplexesexhibitedhighcatalyticactivityforthehydrosilylationofolefinsbytriethoxysilane.Theeffectsoftemperatureandtheamountofcomplexonthecatalyticactivity,aswellastherecoveryandreusabilityofthecatalystswereinvestigated.
简介:新奇的有点芳香的肼,N-(4-(4-(2,6-diphenylpyridine-4-yl)含苯氧基)苯基)-3,5-diaminobezamide(DPDAB),与4-经由3,5-dinitrobenzoylchloride的芳香的亲核的替换被综合(4-(2,6-diphenylpyridine-4-yl)含苯氧基)苯胺(DPPA),由催化钯的肼列在后面减小。这单体被用来commerically与几基于反应准备polyimides(PI)avaiabletetracarboxylicdianhydrides象pyromellaticdianhydride(PMDA)那样,benzophenonetetracarboxylicacidedianhydride(BTDA)和自行车[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylicdianhydride(BCDA)。这些PI在0.340.76dL/g的范围有固有的粘性并且在各种各样的aprotic显示出好溶解度极的溶剂。PI的眼镜转变tempratures(Tgs)在184302的范围
简介:Asidechainliquidcrystallinecopolysiloxane,whichwouldshowelectro-opticeffectsasknownfromlowmassliquidcrystal,wassynthesizedbyhydrosilylationreaction,andthetwohomologousmonomerswithdifferentlengthspacerscontainingSchiff’sbasemesogenwith—NO2terminatedgroupweregraftedtoapolysiloxanemainchain.Residualmonomerincrudeproductiseffectiveinreinforcingtheresponsetoanelectricfieldoverthatofpurepolymericliquidcrystal.