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简介：Thestarch/D,L-lactidegraftcopolymersweresynthesizedbyreactingD,L-lactidewithcornstarchinN,N-dimethylacetamide(DMAM)inthepresenceoftriethylamine(NEt3)andanhydrouslithiumchloride.TheeffectofreactiontimeandthemolarratioofD,L-lactidetoglucosestructuralunitofstarchonmonomerconversion(C%),graft(G%)andgraftefficiency(GE%)werestudied,TheC%,G%andGE%couldapproach37.3%179.7%and68.0%,respectivelywhenthemolarratioofD,L-lactidetoglucosestructuralunitofstarchis10:1andthegraftcopolymerizationwascarriedoutat80-85℃for4hrundernitrogenatmosphere.TheFouriertransformsinfra-red(FTIR)spectroscopy.differentialscanningcalorimetry(DSC)andX_raydiffraction(XRD)spectroscopywereusedinordertocharacterizethegraftcopolymers.FTIRspectrashowthatabsorptionbandat1740cm^-1confirmedtheformationofesterbond,indicatingthestarch/D,L-lactidegraftcopolymerswereproduced,theDSCcharacteristicresultsshowthemeltingtemperatureofthegraftcopolymerwereelevatedslightlyasthemolarratioofD,L-lactidetoglucosestructuralunitsofstarchincreasedandtheX-raydiffractionspectrashowthesynthesizedgraftcopolymerswereamorphous.Thedegradabilityofgraftcopolymerwastestedwiththeaidofacid,alkaliandmicrobesuchasbacillussubtilisandstaphylococcusaureus.Theresultsofwaterrsistanceshowthegraftcopolymerproducedcanbeusedasacomponentofimpermeablecoatingforcardboard.

简介：N-acetyl-D-methionine,NaAcandtheremainsofN-acetyl-L-methioninedramaticallyaffectthepurificationofL-methioninewhenpurifiedfromthemixtureofenzymaticallydeacylatedN-acetyl-DL-methionine,leadingtoalowyieldconventionally.Here,thispaperreportsasuccessfulseparationandpurificationofbothL-methionineandN-acetyl-D-methioninebyanHion-exchangecolumn.ThepH,L-Metconcentrationandtheratiobetweenthecontentofsodiumcationandtheion-exchangecapacitywereoptimizedtoobtainthemaximumyield.Experimentalresultsindicatethat,undertheoptimizedconditions,theyieldsofL-methionineandN-acetyl-D-methioninecanreachashighas85%and75%,respectively.

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简介：Thepolymerizationof1-octeneinitiatedbymethylalumoxane(MAO)-activatedNi(Ⅱ)-based-α-diiminecomplexes[(2,6-i-Pr)_2C_6H_3-DAB(An)]NiBr_2wasinvestigated.Usingthiscatalyst,poly(1-octene)swithmolecularweightbetween100×10~3and400×10~3andpolydispersity(M_w/M_n)between1.3and1.5weresynthesizedsuccessfullybyvaryingreactiontimeatroomtemperature.Thepoly(1-octene)swereamorphouspolymersandcouldbewellsolubleintetrahydrofuran(THF).Afterfractionalprecipitation,poly(1-octene)swithnarrowmolecularweightdistributions(M_w/M_n≤1.12)wereobtained.Theirweight-averagemolecularweightsweremeasuredbygelpermeationchromatography(GPC)inconjunctionwithonlinemodelBI-MwAmultianglelaserlightscattering(MALLS),andtheirintrinsicviscositiesweremeasuredbyMaron'ssingle-pointmethod.ThekandavaluesinMark-Houwinkequation[η]=KM~αinTHFat40℃were0.089mL/gand0.61respectively.

简介：Theinsertionof1,1-bis(1′-naphthyl)ethylenemonomerunitintotheactivepolystyrenechainendgreatlydecreasedthereactivityoftheactivechainendtothecarbonylgroup,andallowedthepolymericchainendtoreactonlywiththedoublebondinN-methacryloylcaprolactam,resultinginN-acylcaprolactamfunctionalizedpolystyrenein100%conversion.Newdiblockcopolymerofpolystyrenewithpolycaprolactamwassynthesizedbydirectreactionofthefunctionalizedpolymerwithcaprolactamwithoutaddingadditionalalkalimetalortheircaprolactamsalts.

简介：1－Ethoxycarbonylalkyldiphenylpolystyrylphosphoniumtriflatescanbeeasilypreparedbyquaternizingdiphenylpolystyrylphosphinewithethyl2-trifloxyalkanoates;basetreatmentofthesepolymer-supportedphosphoniumtriflatesaffords1-ethoxycarbonylalkylidenephosphoraneswhicharestableandundergosatisfactoryWittigreactions.

简介：The1,1'-binaphtholbasedoligomers3and7with3,3'-acetylene-phenylene-acetylenespacerwerepreparedfromBINOL1.ThehighopticalrotationvalueandCDspectrademonstratedthemainchainchiralityoftheoligomermolecule.TheUV-VISandfluorescentspectraevidencethecharacteristicsofconjugatedstructure.Incomparisonwitholigomer2bearing3,3'-acetylenespacer,theoligomers3and7havelongerefficientconjugationsegment,andtheirfluorescentquantumyields(φ)increased(0.60-0.65versus0.14).Extendingtheeffectiveconjugationsegmentwouldimprovethephotophysicalpropertiesofchiralconjugatedpolymers.``

简介：Newmodelcompound1H,1′H-Bis（benz-Δ^4-imidazoline)2,2′-spiro-titaniumdichloridewaspreparedandthestructureofthecompoundwasdeterminedby1R,MSandelementaryanalysis.

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简介：Ｍｅｔａｔｈｅｓｉｓｏｆ１－ＨｅｐｔｅｎｅｏｖｅｒＴｕｎｇｓｔｅｎＣａｔａｌｙｓｔＩｍｍｏｂｉｌｉｚｅｄｏｎＰｏｌｙｍｅｒｓＹａｏＪｉｎｓｈｕｌ；ＬｉＨｏｎｇ；ＳｕｎＪｕｎｔａｎ；ＨｅＢｉｎｇｌｉｎ（ＩｎｓｔｉｔｕｔｅｏｆＰｏｌｙｍｅｒＣｈｅｍｉｓｔ...

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：Aseriesof1-naphthylmethylmethacrylate（NMMA）-methylmethacrylate（MMA）copolymersweresynthesizedonfreeradicalmechanism.ThereactivityratiosofNMMA（r1）andMMA（r2）werereportedtobe0.83and0.89,respectively.ThecharacterizationofthecopolymersbyusingIR,NMR,GPC,UVandfiuorescencespectrometrywasdescribedinthispaper.

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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.

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