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

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.

简介：TheexchangebehaviorsofWO4^2-,MoO4^2-,H2W12O46^6-andMo8O26^4-anionswithinmacroporousexchangeresin(D290)phaseshavebeenstudied.Thevaluesofdiffusionconstant(B),innerdiffusioncoefficient(D^-),retartedtime(τd)half-exchange-period(t1/2),andactivationenergy(ΔE）werefoundfromthekineticanalyses.AnewmethodtoseparateW(VI)andMo(VI)fromeachotherwasalsosuggested.

简介：Fourkindsofpalladiumcatalystsdispersedonpoly-N-vinyl-2-pyrrolidonewerepreparedbyusingCH3OH-NaOH,NaBH4,H2OorCH3OH-H2Oasthereducingagentintheprocessofcatalystpreparation.ThecatalystswerecharacterizedbyXPS,TEM,XRDandusedforthehydrogenationofmethylacrylate.Itwasfoundthatthevalencestateofpalladiumanddistributionofpalladiumparticlesaswellasthehydrogenationrateweregreatlyaffectedbythereducingagent.ThebestevenlydispersedpalladiumcatalystshowinghighhydrogenationactivitywaspreparedusingCH3OH-NaOHasthereducingagent.

简介：Anewkindofmonomerswassuccessfullysynthesizedbythereactionbetween2-chloromethylcycloketalandtrimethylsilylcyanide,followedbyringclosureanddehaiogenation.Polymerizationsofthemonomerswerecarriedoutinbenzenesolutionat80℃withbenzoylperoxideasinitiator.BoththestructuresofmonomersandpolymerswerecharacterizedbyIR,1HNMR,13CNMRandelementalanalysis.

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简介：TheNdCl3/MgCl2bisupportedcatalystwaspreparedbyusingNdCl3,MgCl2,（CH3）2（CH2）2OHandTiCl4.ItisshownthatthestructureofbisupportedcatalystwasdifferentfromthoseofeitherNdCl3orMgCl2singlesupportedcatalyst.Apeculiartypeofkineticcurveforethylenepolymerizationwasfound.

简介：Polyfluoroalkylsubstituted2-hydroxyethylacrylate6wassynthesizedinsixstepsusingglycerolasastartingmaterial.Apreliminaryinvestigationhasbeentakenonthesynthesisandcharacterizationofcopolymersof6and2-hydroxyethylmethacrylate.

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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.

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简介：Thisworkdealswiththekineticsofco-condensationpolymerizationofAB2andABmonomers,givingexpressionsofthetwo-dimensionalmolecularweightdistributionfunctionandthenumber/weightaveragemolecularweightsoftheresultingcopolymers.Thetwo-dimensionalmolecularweightdistributiondependsontwoindices,nandl,whicharetherespectivenumbersofAB2andABunitsinacopolymerspecies.Theevolutionofthetwo-dimensionalweightandzdistributionsduringtheco-condensationpolymerizationhasbeenevaluatedsystematically.Finally,thetwo-dimensionaldistributionwastransformedintoaone-dimensionalmolecularweightdistributionwithonlyonevariable(themolecularweightoftheproductsinsteadofthedegreeofpolymerization).Thecalculatedresultsshowthatthehighlybranchedcopolymerhasaverybroadmolecularweightdistributionwhentheco-condensationpolymerizationapproachescompletion.

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：2－Hydroxyethylacrylateissynthesizedfromacrylicacidandethyleneglycolunderasimpleandmildconditionbyusingstrongacidiccationionexchangeresinasacatalyst,whichcouldberecycledaslongas10timeswithhighactivation.

简介：TheanalyticalexpressionsofthevariousstructuralunitsandtheaveragedegreeofbranchingforthehyperbranchedpolymersresultedfromAB_2polycondensationwithsubstitutioneffectwerederivedbythekineticmechanism.ThereactivitydifferencebetweentheBgroupinlinearunitandthatinterminalgrouphasgreateffectonthemolecularparametersoftheproductsobtained.TheconcentrationofterminalunitshasamaximumwiththeincreaseoftheconversionofAgroups(x).Thehigherthereactivityratio(r)oflinearBgrouptobranchedoneis,thelaterthemaximumappearsandthelargeritis.Thedegreeofbranchingofthehyperbranchedpolymersobtainediscontrollablebyadjustingtheparametersofrandx,whichincreaseswithincreasingbothxandr.

简介：Animprovedmethodisdevelopedbyusingstronglyacidiccationexchangeresin(001×1，H^+form)asacatalystforthesynthesisofdiphenyl1-(N-benzyloxycarbonyl-amino)alkanephosphonatesand1-(N-benzyloxycarbonylamino)alkanephenylphosphinicacidsinhighyields.

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