简介：TenfractionatedsamplesofChineselacquerpolysaccharideinaqueous0.1MNaC1solutionwerestudiedbyaqueous-phasegelpermeationchromatography(GPC).Theuniversalcalibration,broadMWDcalibrationandcorrectedcolumndispersionwereadoptedtotheanalysisofGPCchromatogramsofthepolysaccharide.ThemolecularweightsM_w,M_nandpolydispersityindexM_w/M_nobtainedfromGPCareingoodagreementwiththeresultsoflightscatteringandmembraneosmometry.Itisverifiedthattheuniversalcalibrationconceptisapplicabletothelacquerpolysaccharidehavinganumberofsidechains.

简介：Cationic聚合物作为非病毒的基因向量一直在收到许多注意。水的活动阶段为尺寸排除与ShodexOHpakSB列在联合被优化层析(秒)分析包含二硫化物(乙烯imine)(PEI)poly，衍生物在基因交货使用了。在活动阶段的acetonitrile的增加被显示能压制在聚合物analytes和静止阶段之间的恐水病的相互作用。cationic聚合物的绝对分子的重量和分布从联机SEC-MALS(散布的多角度光)直接被决定/RI(折射索引察觉者)。结果证明在基因交货使用，小乐队拓宽的包含二硫化物的PEI衍生物的好秒分离被完成。

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简介：Themolecularstructureofpolyethylene（PE）sampleswithvariouscomonomersincludingpropylene,1-buteneand1-hexenewasinvestigatedbyDSCand13C-NMRtechniques.Thedensityofthesamplesvariesfrom0.948g/cm3to0.917g/cm3,andthemolecularweightdeterminedbytheGPCmethodisintherangeof1～2×105.Thebranchpointcontentofthesampleswasdeterminedby13C-NMRmeasurementsandwasfoundtobelessthan20per1000Catomsalongthemainchain.CrystallizationsegregationDSCtechnique（CSDSC）wasusedtocharacterizethebranchpointdistributionorthesegmentlengthdistributionofPEs.Thecrystallizationsegregationwasperformedinasuccessiveannealingprocessatdecreasingtemperatures.Theintervaloftwosuccessiveannealingtemperatureswas6K,andthetimelengthofeachannealingstepwas2.5h.TheCSDSCresultsclearlyindicatethatallthePEsamplesused,includingsomemetallocenePEs,moreorlessexhibittheirnon-uniformityinsegmentlengthdistribution,andbimodalormultimodalCSDSCcurveswereusuallyobserved.ForquantitativecharacterizationoftheCSDSCcurvesandthesegmentlengthdistributiontwoparameters,theaveragemeltingpoint,TmAV,andtheroot-mean-squaredeviationofmeltingtemperature,(ΔTmAV2)1/2,wereproposed.TmAViscorrespondingtotheaveragesegmentlengthduetobranchingand(ΔTmAV2)1/2givesinformationaboutthewidthofthesegmentlengthdistribution.Experimentalresultsshowthatboththedegreeofaveragemeltingtemperaturedepressionandthewidthofthedistributionseemtoincreasewithincreasingthebranchingcontentandaredependentonthetypeofcomonomers.VerygoodreproducibilityandadditivityoftheCSDSCmethodwereevidencedexperimentally.ItwasconcludedthattheCSDSCtechniqueisasensitiveandconvenientmethodforcharacterizingthesegmentlengthdistributionofbr

简介：Polymerchaincoilswithentanglementisacrucialscaleofstructuresinpolymermaterialssincetheirrelaxationtimesarematchingpracticalprocessingtimes.Basedonthephenomenologicalmodelofpolymerchaincoilsandanewfiniteelementapproach,wehavedesignedacomputersoftwareincludingsolver,pre-andpost-processingmodules,anddevelopedadigitalanalysistechnologyforthemorphologyofpolymerchaincoilsinflowfields(DAMPC).Usingthistechnologywemaysimulatethemorphologydevelopmentofchaincoilsinvariousflowfields,suchassimpleshearflow,elongationalflow,andanycomplexflowattransientorsteadystate.Theapplicationsmadeuptonowshowthatthesoftwarepredictionsarecomparablewithexperimentalresults.

简介：Thetransitionbehaviouroftheblendsofisotacticpolypropylene(i-PP)withethylene-propyleneterpolymer(EPDM)containing42wt%propylenewasinvestigatedbydynamicmechanicalanalysistechnique(DMA).Owingtoitshighpropylenecontent,EPDMiscompatiblewithi-PPtosomedegree.Theinteractionbetweenthetwocomponentswasstrengthened.Asexpected,forpartiallycompatiblesystemtheglasstransitiontemperatureofi-PPintheblendsshiftedtolowertemperature.Itwasfoundthatthereexistedtwotransitions,αEPDMandβEPDM,fortheEPDMusedinthiswork.TheformerwasconsideredtobetheglasstransitionoftherandomchainsegmentsofEPDM,whilethelatterthelocalmotionofthelongethylenesequencesinEPDM.TheunusualtransitionbehaviourofαEPDMintheblendswasexplainedintermsofthegreaterthermalexpansionofEPDMandthecompatibilityofthetwocomponents.Ontheotherhand,theβEPDMchangedwiththecompositionoftheblendsinaregularmanner.

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

简介：Thedigitalimageprocessingtechniquewasusedfortheextractionofphysicalinformationfromthetemporalimageofphasestructureintheprocessofphaseseparationintheblendofpoly(butyleneterephthalate-co-caprolactone)withpolycarbonate.Thepowerspectrumimagesofthetwo-dimensionalFouriertransformation(2DFT)ofthetemporalimageofphasestructurereflectthechangeofthephasesizewithtime.

简介：X-rayphotoelectronspectroscopy(XPS)wasadoptedtoelucidatesorptionmechanismofphenolandp-nitrophenolontoaweaklyanionexchangerD301.ThedistributionofspecificformsoftertiaryaminogrouponD301wasobtainedandeffectoffreetertiaryaminogrouponphenolsorptionontoD301wasdiscussed.TheresultindicatedthatthepercentoftheprotonatedtertiaryaminegrouponpolymericmatrixwasmuchlowerthanthereferencecompoundN,N-dimethylbenzylamineatanidenticalpHvalueinsolutionduetothemuchloweractivitydegreeofhydrogenionininnerresinphasethanintheexternalsolution.LessfreeaminogrouponD301resultsinlesssorptioncapacityofphenolandp-nitrophenolinanacidicsolution.UndertheexperimentalconditionsbothphenolsorptionontoD301canbeexplainedassolidextractionandthedistributioncoefficientvarieslinearlywiththecontentoffreeaminogrouponD301.

简介：我们重游聚合物液体的Simha-Somcynsky模型以达到开发新奇理论、计算的途径简化并且加快它的解决方案以及试验性的数据的试穿，并且减少它数学复杂性的水平。我们报导允许我们确切解决模型的二个方程之一的一个新奇方法，因此把数学困难的水平放等同于一其它为聚合物液体当模特儿。而且，我们描述能够以一个不偏的方法适合模型的所有五个参数的一个计算算法。获得的结果复制文学结果并且很精确地为三聚合物适合试验性的pressure-volume-temperature和溶解度参数数据。而且，新技术允许在很低的温度的模型的调查。出人意料地，模型预言当习惯性地在dilatometry观察了，能作为一只杯子被解释的行为转移，微分扫描热量测定，和一只杯子分阶段执行。我们比较了预言并且试验性的T<潜水艇class=“a-plus-plus”>g为cis的spoly(1,4丁二烯)并且发现一个优秀量的协议。