简介:ThephysicalandchemicalpropertiesofFFA-1ionexchangefiberhavebeencharacterizedwithIRspectrum,thermalanalysisandSEMmeans.ThepHtitrationcurve,swellingrate,mechanicalproperties,resistancedropoffilterlayeraswellasthedynamicadsorptionforSO2wasdetermined.TheseexperimentsprovidedtheessentialparametersforthepracticalapplicationofFFA-1materialinadsorptionoftoxicgases.
简介:Aseriesof1-naphthylmethylmethacrylate(NMMA)-methylmethacrylate(MMA)copolymersweresynthesizedonfreeradicalmechanism.ThereactivityratiosofNMMA(r1)andMMA(r2)werereportedtobe0.83and0.89,respectively.ThecharacterizationofthecopolymersbyusingIR,NMR,GPC,UVandfiuorescencespectrometrywasdescribedinthispaper.
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:Transesterificationbetweenmethyl-butyrateand1-butanolinnonaqueoussystemswascatalyzedbyporcinepancreaticlipasewhichwasimmobilizedoncross-linkedpolystyrene.Organicsolvents,substrateconcentration,contentsofwaterandotherparameterswhichaffecttheimmobilizedenzymeactivitywerestudied.Lipaseimmobilizedonhydrophobiccrosslinkedpolystyrenecanreduceitsdiffusionlimitinthereaction.Itwasfoundthattheactivityofimmobilizedlipaseinorganicsystemswastwotimesashighasthatoffreelipase.
简介:Fluorescencespectraofladderlikepolyphenylsilsesquioxane(LPPS)andladderlike1,4-phenylene-bridgedpolyvinylsiloxane(LPPVS)havebeenmeasuredasafunctionoftemperature(4-55℃),indilutetetrahydrofuransolution.Theexcimer(IE)tomonomer(IM)intensityratio(IE/IM)ofLPPSdilutesolutionshowsadoublelinearArrheniusplotwithabreakpointascribabletoatransitiontemperatureTr.Thisbehaviorhasnotbeenfoundforsinglechainpolyorganosiloxanes.WhenIn/EofLPPSwasplottedagainst1/T,italsogaveadoublelinearplotwithonebreakpoint,whichwasfoundinsinglechainpolyorganosiloxanes.ThedifferentbehaviorsbetweenLPPSandsinglechainpolyorganosiloxanesmaybemainlyattributedtotherelativelyrigiddouble-chainmacromolecularbackboneofLPPS.However,theln(IE/IM)ofdiluteLPPVSsolutionversus1/Tshowsasimplelinearvariationwithapositiveslopewhichconfirmsourproposition.ThedifferencebetweenthefluorescenceresultsofLPPSandthoseofLPPVSmaypossiblyderivefromtheirstructuredifferencesandcooperativemotioninbackbonechainbonds.
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:Dithia-monoaza18-Crown-6anditsimmobilizationproduct,silica-bound1,7-dithia-4-aza-10,13,16-trioxa-cyclooctadecaneviaaspacerofthreecarbonatoms,anditsplatinumcomplexhavebeensynthesized.Itisfoundthattheplatinumcomplexisanefficienthydrosilylationcatalystforolefins.TheXPSdataoftheplatinumcomplexarereported.
简介:包含磷氮(MSMM-Al-P)的新奇包含的火焰retardant被与聚酰胺66包含准备(PA66-MSMM-Al-P)为聚酰胺6的火焰延迟(PA6)。结构和PA66-MSMM-Al-P的热性质被Fourier变换红外线的光谱学,X光检查光电子光谱学和thermogravimetric分析描绘。包含火焰retardants(MSMMAl-P和PA66-MSMM-Al-P)的PA6易燃被限制的氧索引测试,垂直燃烧测试和锥热量计调查。火焰retardancy和锥calorimetric分析在flame-retardantPA6建议了在PA66和MSMM-Al-P之间的synergistic效果。flame-retardantPA6的热稳定性也被调查。
简介:TheL-proline-functionalizedpolystyrenewith1-methyldecylenespacerwassynthesizedfrom2%divinylbenzene-crosslinkedpolystyrenegelvia10-bromo-1-methyldecylpolystyreneintermediate.Aftercomplexedwithcopper(Ⅱ)ion,thepolymerwithL-prolineligandwasusedasthechiralstationaryphase(CSP)forligandexchangechromatographyofaminoacidracemates.TheresultsshowedthattheCSPpossessedpowerfulenantioselectivityandallracematesofthefifteentriedaminoacidswerecompletelyseparated.
简介:Inordertoimprovetheflexibilityofpoly(propylenecarbonate)(PPC),poly(1,2-propylenesuccinate)(PPSu)wasusedtoplasticizePPCinabatchmixer.TheeffectsofPPSuonthemiscibility,thermalstability,mechanicalandrheologicalpropertiesoftheblendswereinvestigated.PPCwaspartiallymisciblewithPPSu.ItwasdemonstratedthatPPSudecreasedtheglasstransitiontemperatureandmeltviscosityofPPC,asshownintheDSCandrheologicalcurves.WiththeincreaseinPPSucontent,thePPC/PPSublendsshoweddecreasedtensilestrength,however,theelongationatbreakwasincreasedto1100%forthe70/30PPC/PPSublend.TheintroductionofPPSuprovidedanefficientandnovelplasticizationmethodtoextendtheapplicationareaofPPC.
简介:Thestructureofpolyimidefrom1,4-bis(3’,4’-dicarboxyphenoxy)benzeneand4,4’-oxydianilinefilmspecimensbeforeandafterhotstretchinghasbeeninvestigatedbyWAXD,DSCandFTIR.AsevidencedbyboththeWAXDandDSCresults,itcouldbebelievedthatstraininducedcrystallizationdidtakeplaceafterhotstretching.Meanwhile,shiftingpositionandsplittingofsomebandpeaksexistedontheFTIRspectrogramswereexplainedintermsoftheclosepackingofchainsandthechangesofinter-molecularcharge-transferinteractionbetweenimidegroupsandaromaticgroupsuponcrystallization.
简介:ThetreatmentofsalicylicacidmanufacturingwastewaterbyNDA-100resinwasinvestigated.ThesorptionintensityofphenolwasfoundtobestronglydependentonpHoftheaqueousphase.EquilibriumadsorptiondatafittobothLangmuirandFreundlichmodels.ThecolumnadsorptionshowedthatthisprocesswassuitableforthetreatmentofsalicylicacidmanufacturingwastewaterAbout99.9%CODcrremovalwasobtainedundertheoptimaloperatingconditions.Theresincouldbecompletelyregeneratedwith1BV8%(w/w)NaOH+2BVH2O,therecoveryof98.9%ofthesubstancewasreached.Thisprocessmakesitpossibletorecoverthevaluablematerialfromthewastewaterandtoimprovetheeffluentwaterquality.