简介：Isotacticpoly(butene-1)(iPB)withsphericalmorphologywassynthesizedsuccessfullywithbulkprecipitationpolymerizationwithoutpost-treatmentoftheproducts.ThebulkprecipitationpolymerizationprocessmadeitpossibleforiPBtobeusedasgeneralplasticduetotheacceptabledecreasedcostcomparedwiththesolutionpolymerizationprocess.TheinfluenceofcatalystresiduesontheagingandthermalstabilityofiPBsynthesizedbybulkprecipitationpolymerizationmethodwasinvestigatedbygelpermeationchromatography,mechanicalperformancetesting,thermogravimetricanalysisandinfraredspectroscopicanalysis.CommercialiPBandthelab-madeiPBwithvariedcatalystresiduecontentswerestudied.TheresultsdemonstratedthatthecatalystresiduesplayedanimportantroleintheagingprocessoftheiPB.Apossiblemechanismofagingpromotionbycatalystresidueswasproposed.

简介：Polymer-supportedRCpCpTiCl2(Cp=η^5-C5H4;RCp=η^5-RC5H4)havebeenpreparedandreducedbyi-C3H7MgBrinsitu，thenusedincatalyticisomerizationof1,5-hexadiene.Theisomerizationof1,5-hexadieneleadstoamixtureofcyclicandlinearproducts.Theratioofcyclictolinearproductdependsonthenatureofthesupporterandthesubstituentonthecyclopentadienylring.Theformercontributesthemost,forexample,silicasupportedCp2TiCl2gavecyclic-linearratioof99/1,whileforpolymer-supportedCp2TiCl2species,linearcompoundsarethemajorproductsandtheratioofcyclictolinearproductchangeswithdifferentRgroupsonthecyclopentadienylring.

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.

简介：Thecopolymerizationofp-diethynylbenzene（PDEB）withphenylacetylene（PhA）,4,4’-diethynylbiphenyl（DEBP）orm-diethynylbenzene（MDEB）arestudiedbyvaryingmoleratiosofmonomers.WhenthemoleratiosofPDEB/PhAarelessorequalto1/5,thecopolymersaresolubleandfusible,buttheothercopolymersareinsolubleandinfusible.Theresultsshowthatthegoodsolventofcross-linkedcopolymersisbenzeneandtheirsolubilityparameteris9.15cal0.5.cm（-1.5）.Andtheirswellability（θp）,Hugginsparameter（χ）,density(d425)andtheaveragemolecularweightsbetweencrosslinks（c）aremeasured.Itisfoundthatθpandcofcopolymersaregreaterbutd425islessthanthatofrespectivehomopolymers.IRspectrashowthatthecopolymershavetransoidconfigurationandsmallnumberofunreactedethynylgroupsexistinthecopolymers.Themechanismaboutthepolymerizationoracetylenicderivativesinitiatedby（Ph3P）2PdCl2isdiscussed.

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：Poly(methylmetacrylate)(PMMA)/Y0.0025Si0.025Ba0.9725(Ti(0.9)Sn0.1)O3(YBTS)composites在YBTS的不同重量比率被准备(0wt%，5wt%，10wt%和20wt%YBTS)招待以便在PMMA的电、光的性质上调查YBTS增加的效果。电的性质(阻抗，绝缘的经常的绝缘的损失和交流电导率)在频率范围被学习10kHz-1MHz并且在温度范围20鈥?0掳C。在增加YBTS的内容之上陶器，我们在在绝缘的经常的、绝缘的损失和PMMA的交流电导率的阻抗和增加观察了减小主人。我们也发现在高YBTS内容的松驰过程由于在离子的传导性的松驰。吸收系数(伪)在波长范围被决定了230鈥?在为所有YBTS-PMMAcomposites的房间温度的00nm。而且，YBTS的增加陶器高度特别在300nm下面提高PMMA主人的紫外吸收。对PMMA主人陶器的20wt%YBTS的增加减少从5eV的光精力差距到3.41eV。关联在之间电，光并且SEM结果被报导。关键词电-光-PMMA，陶器-铁电体-Composites

简介：Dithia-monoaza18-Crown-6anditsimmobilizationproduct,silica-bound1,7-dithia-4-aza-10,13,16-trioxa-cyclooctadecaneviaaspacerofthreecarbonatoms,anditsplatinumcomplexhavebeensynthesized.Itisfoundthattheplatinumcomplexisanefficienthydrosilylationcatalystforolefins.TheXPSdataoftheplatinumcomplexarereported.

简介：TheL-proline-functionalizedpolystyrenewith1-methyldecylenespacerwassynthesizedfrom2%divinylbenzene-crosslinkedpolystyrenegelvia10-bromo-1-methyldecylpolystyreneintermediate.Aftercomplexedwithcopper(Ⅱ）ion,thepolymerwithL-prolineligandwasusedasthechiralstationaryphase(CSP)forligandexchangechromatographyofaminoacidracemates.TheresultsshowedthattheCSPpossessedpowerfulenantioselectivityandallracematesofthefifteentriedaminoacidswerecompletelyseparated.

简介：

简介：Cobaltandnickelcomplexes(1a-1dand2a-2d,respectively)supportedby2-imidate-pyridineligandsweresynthesizedandusedfor1,3-butadienepolymerization.ThecomplexeswerecharacterizedbyIRandelementanalysis,andcomplex1awasfurthercharacterizedbysingle-crystalX-raydiffraction.Thesolidstatestructureofcomplex1adisplayedadistortedtetrahedralgeometry.Uponactivationwithethylaluminumsesquichloride(EASC),allthecomplexesshowedhighactivitiestoward1,3-butadienepolymerization.Thecobaltcomplexesproducedpolymerswithhighcis-1,4contentsandhighmolecularweights,whilethenickelcomplexesdisplayedlowcis-1,4selectivityandtheresultingpolymershadlowmolecularweights.Thecatalyticactivitiesofthecomplexeshighlydependedontheligandstructure.Withtheincrementofpolymerizationtemperature,thecis-1,4contentandthemolecularweightoftheresultingpolymerdecreased.

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：Fivenewopticallyactivepolyamides(PAs)6a-6ewerepreparedbydirectpolycondensationreactionof2-(1,3-isoindolinedione-2-yl)-glutaricacid4asanewchiraldiacidwithvariousaromaticdiamines5a-5einamediumconsistingoftriphenylphosphite(TPP),calciumchloride,pyridine(Py)andN-methyl-2-pyrrolidone(NMP).Thepolycondensationreactionproducedaseriesofpolyamids6a-6einquantitativeyieldswithinherentviscositiesof0.26-0.39dL/g.Theresultingpolymerswerefullycharacterizedbymeansof~1H-NMR,FT-IRspectroscopy,elementalanalysis,inherentviscosityandspecificrotation.Thermalpropertiesofthesepolymerswereinvestigatedusingthermalgravimetricanalysis(TGA)anddifferentialthermalgravimetry(DTG).PhthalimideringsasabulkypendentgroupinthepolymerchainsdisturbtheinterchainandintrachaininteractionsandmakethesePAsreadilysolubleinpolar,aproticsolventssuchasN,N-dimethylacetamide(DMAc),N,N-dimethylformamide(DMF),dimethylsulfoxide(DMSO),N-methyl-2-pyrrolidone(NMP)andsulfuricacid.

简介：Usingsupportedmulti-componentzincdicarboxylatecatalyst,poly(1,2-propylenecarbonate-co-1,2-cyclohexylenecarbonate)(PPCHC)wassuccessfullysynthesizedfromcarbondioxide(CO_2)withpropyleneoxide(PO)andcyclohexeneoxide(CHO).Theconversionofepoxidesdramaticallyincreasedupto89.7%(yield:384.2gofpolymerpergofZn)withincreasingreactiontemperaturefrom60℃to80℃.Theoptimizedreactiontemperatureis80℃.Thechemicalstructure,themolecularweight,aswellasthermalandmechanicalpropertiesoftheresultingterpolymerswereinvestigatedextensively.WhenCHOfeedcontent(mol%)islowerthan10%,thePPCHCterpolymershavenumberaveragemolecularweight(M_n)rangingfrom102×10~3to202×10~3andmolecularweightdistribution(MWD)valuesrangingfrom2.8to3.5.Incontrasttopoly(propylenecarbonate)(PPC),theintroductionofsmallamountofCHOleadstoincreaseintheglasstransitiontemperaturefrom38.0℃to42.6℃.Similarly,themechanicalstrengthofthesynthesizedterpolymerisgreatlyenhancedduetotheincorporationofCHO.TheseimprovementsinmechanicalandthermalpropertiesareofimportanceforthepracticalapplicationofPPC.