简介:LigandeffectofthecatalyticsystemWCl6-Et2AlClforringopeningmetathesispolymerization(ROMP)ofdicyclopentadiene(DCPD)wasinvestigated.Theexperimentalresultsshowthataddingstericallyhinderedphenol-2.6-di-tert-butylcresylol(DTBC)inthecatalyticsystemnotonlycanobviouslyincreasethemonomerconversionofpolymerizationbutalsoimprovethemechanicalproperties,suchasnotchedimpactstrength(NIS),tensilestrength(TS)ect.,ofthesynthesizedpolydicyclopentadiene(PDCPD),Asimilareffectcanbeobservedbyusingastericallyhinderdpolymericphenol-linearphenolformaldehyderesin(LPF)asaligand.
简介:Anovelpolymercontainingthesucrosegroupwassynthesizedbyradicalpolymerizationfromanenzymaticallypreparedmonomer,1′-O-vinyladipoyl-sucrose(VAS).TransesterificationreactionofsucrosewithdivinyladipateinanhydrouspyridinecatalyzedbyanalkalineproteasefromBacillussubtilisat60℃for7daysgaveVAS(yield55%)withoutanyblocking/deblockingsteps.ThevinylsucroseestercouldbepolymerizedwithpotassiumpersulfateandH2O2asinitiatortogivepoly(1′-O-vinyladipoyl-sucrose)withMn=33,000andMw=53,200,Mw/Mn=1.61.Thepolymerwasbiodegradable.After6daysinaqueousbuffer(pH7),thisalkalineproteasecoulddegradepoly(1′-O-vinyladipoyl-sucrose)toMnofca.1080,Mw/Mn=3.30(37℃),andMnofca.5200,Mw/Mn=2.44(4℃).Thepolymercontainingthesucrosebranchwouldbeafunctionalmaterialinvariousapplicationfields.
简介:Thecopolymerizationofl-octenewithstyrenecatalyzedbyrareearthcoordinationcatalystshasbeenstudiedforthefirsttime.Somefeaturesandkineticbehavioraredescribed.Theoverallactivationenergyofthecopolymerizationwas22.2KJ/molandthecopolymerizationratecouldbeexpressedasRp=Kp[Nd][M]2.(=1.68×10-3L2/mol2.S,50℃,[Oct]/[St]=1).ThecatalyticactivityofvariousrareearthelementsinLn(naph)3forthecopolymerizationwascomparedandshowsthefollowingsequence:Dy,Y,Yb>Ho>Sm,Gd,Nd>Pr>Ce>La>Tm.Bothmonomersofl-octeneandstyreneinthecopolymerizationbyNd(naph)3-AlEt3havethetendencyofconstantproportioncopolymerization.Thestructureofthecopolymerswasstudiedby1H-NMR.
简介:ThephysicalandchemicalpropertiesofFFA-1ionexchangefiberhavebeencharacterizedwithIRspectrum,thermalanalysisandSEMmeans.ThepHtitrationcurve,swellingrate,mechanicalproperties,resistancedropoffilterlayeraswellasthedynamicadsorptionforSO2wasdetermined.TheseexperimentsprovidedtheessentialparametersforthepracticalapplicationofFFA-1materialinadsorptionoftoxicgases.
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:Aseriesof1-naphthylmethylmethacrylate(NMMA)-methylmethacrylate(MMA)copolymersweresynthesizedonfreeradicalmechanism.ThereactivityratiosofNMMA(r1)andMMA(r2)werereportedtobe0.83and0.89,respectively.ThecharacterizationofthecopolymersbyusingIR,NMR,GPC,UVandfiuorescencespectrometrywasdescribedinthispaper.
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:Animprovedmethodisdevelopedbyusingstronglyacidiccationexchangeresin(001×1,H^+form)asacatalystforthesynthesisofdiphenyl1-(N-benzyloxycarbonyl-amino)alkanephosphonatesand1-(N-benzyloxycarbonylamino)alkanephenylphosphinicacidsinhighyields.
简介:Anovelpolymer-bound1,2-diol,3-polystyrylsulfonyl-1,2-propanediol(6)hadbeenpreparedbythereactionofsodiumpolystyrylsulfinatewithallylbromide,followedbyoxidationand.hydrolysisordirectlywith3-chloro-1,2-propanediolinthepresenceofaphasetransfercatalyst,n-tetrabutylammoniumiodide.Thecapacityofresin6forterephthaidehydereached1.43mmol/g.Thealdehydicgroupsattachedtopolymer6reactedwithhydroxylaminehydrochlorideorreducedbysodiumborohydridegivingp-formylbenzaldoxime(yield:89%)andp-formyl-benzalcohol(yield:734%),respectively.Thehighyieldsofthesepolymer-supportedreactionsshowedthatthepolymer6possessedtheeffectiveisolationofitsreactivesites.
简介:Theadsorptiondynamicsforphenolinaqueoussolutionoftheadsorbentbasedonpolystyrenewasstudied.InordertodistinguishwiththeBoydquasi-homogeneousmodeloftheinnerstructureofion-exchanger,theparticlediffusionmodelincludingsurfacediffustionmodelandporediffusionmodelwassuggestedwhichissuitabletothemacroporousadsorbent.Thediffusiondeterminationstepoftheadsorptionpocesswasestablishedandtheeffectivediffusioncoefficientwasalsodetermined.Theinfluenceofsurfacediffusionandporedifusionontheparticlediffusionratewasinvestigatedqualitatively.Allofthesewereveryimportanttoimprovethestructureofthemacroporousadsorbentinordertoimprovethemass-transferrate.
简介:Fluorescencepropertiesofaseriesofstyrene/p-divinylbenzene(St/p-DVB)copolymerbeadswereinvestigatedbysteady-statefluorescencespectra.Inadditiontothefluorescenceofthephenylringexcimer,anewemissionbandatca395nmappearswhenp-DVBcontentinfeedishigherthan13%(wt).Theintensityofthisnewemissionwasfoundtochangewithp-DVBcontentandtodecreasewithswollenbeads.Theoriginofthisnewemissionisconsideredtobeamulti-ringexcimerformation.
简介:Isotacticpoly(butene-1)(iPB)withsphericalmorphologywassynthesizedsuccessfullywithbulkprecipitationpolymerizationwithoutpost-treatmentoftheproducts.ThebulkprecipitationpolymerizationprocessmadeitpossibleforiPBtobeusedasgeneralplasticduetotheacceptabledecreasedcostcomparedwiththesolutionpolymerizationprocess.TheinfluenceofcatalystresiduesontheagingandthermalstabilityofiPBsynthesizedbybulkprecipitationpolymerizationmethodwasinvestigatedbygelpermeationchromatography,mechanicalperformancetesting,thermogravimetricanalysisandinfraredspectroscopicanalysis.CommercialiPBandthelab-madeiPBwithvariedcatalystresiduecontentswerestudied.TheresultsdemonstratedthatthecatalystresiduesplayedanimportantroleintheagingprocessoftheiPB.Apossiblemechanismofagingpromotionbycatalystresidueswasproposed.
简介:Thetreatmentandresourcereuseof1,2,4-acidproducingwastewaterbyself-mademacroporousadsorptionresinND,A-107wasstudiedinthispaper.Optimumadsorptionanddesorptionprocessparameterswereacquiredbysystematicallystudy.ThepolymericresinNDA-107indicatedgoodadsorption&desorptionof1,2,4-acidinthewastewater.Theremovalefficiencyof1,2,4-acid,CODerisabout78%,72%respectively.Itisevidentthatthisadsorptionprocessisanefficienttreatmentmethodfor1,2,4-acidproducingwastewater.Atthesametime,theaccumulationandresourcereuseofl,2,4-acidcanberealizedinthisprocess.