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26 个结果
  • 简介:Theoneplusone(1+1)modeofhydrosilationreactionofladderlikecis-isotaticpolyallylsilsesquioxane(AllyI-T)andpolyhydrosilsesquioxane(H-T)usingdicyclopentadienylplatinumdichloride(Cp2PtCl2)asthecatalystleadstotheformationofanewpolyorganosiloxane(POS).ThepresenceofnanoscaletubularstructureintheproductPOSwaspreliminarilyprovedbyIR,1H-NMR,differentialscanningcalorimetry(DSC),X-raydiffraction(XRD),gelpermeationchromatography(GPC),atomicforcemicroscopy(AFM)andmolecularsimulation.

  • 标签: Hydrosilylation Polyorganosiloxane Self-assembly TUBULAR structure
  • 简介:Thestructureofpolyimidefrom1,4-bis(3’,4’-dicarboxyphenoxy)benzeneand4,4’-oxydianilinefilmspecimensbeforeandafterhotstretchinghasbeeninvestigatedbyWAXD,DSCandFTIR.AsevidencedbyboththeWAXDandDSCresults,itcouldbebelievedthatstraininducedcrystallizationdidtakeplaceafterhotstretching.Meanwhile,shiftingpositionandsplittingofsomebandpeaksexistedontheFTIRspectrogramswereexplainedintermsoftheclosepackingofchainsandthechangesofinter-molecularcharge-transferinteractionbetweenimidegroupsandaromaticgroupsuponcrystallization.

  • 标签: POLYIMIDE ORIENTATION CRYSTALLIZATION FTIR
  • 简介:Theglassytransitionofthepolyethyleneterephthalate(PET)sampleswhichhavebeensubjectedtosolventinducedcrystallization(SINC)wasinvestigatedbymodulateddifferentialscanningcalorimetry(MDSC)anddensitymeasurement.Thedif-ferentialofheatcapacitysignal,dC_p/dTfromMDSC,wasusedtomonitortheSINCprocess.ItrevealsthattheT_gtemperatureshiftstohighervaluewiththeadvancementofSINC.Whenthetoluene-immersingtimewaslonger(168h),thedetectionofT_gbecomemoredifficult,becausesomesmallerpeaksemergedatthelowertemperaturesandtheseareexplainedasthemovementofsmallsegmentsintheamorphousregion.TheseobservedresultsareduetothemorphologyandstructureintroducedbytheSINCprocess.

  • 标签: MODULATED DSC POLYETHYLENE TEREPHTHALATE SINC
  • 简介:在这份报纸,CD衍生物的三种不同类型作为原子转移激进分子聚合(ATRP)被综合开始者或可逆增加破碎链转移聚合(木排)链转移。为每衍生物的替换的度小心地被描绘通过<啜class=“a-plus-plus”>1H-NMR,<啜class=“a-plus-plus”>13C-NMR光谱学和飞行团spectrometry(MALDI-TOF-MS)的帮助矩阵的激光解吸附作用/电离时间。影响替换的度的因素被讨论。而且,在ATRP和木排之间的比较在N-isopropylacrylamide(NIPAM)的聚合被显示出。

  • 标签: MALDI-TOF-MS RAFT ATRP 链转移 原子转移自由基聚合 合成
  • 简介:新印离子的聚合物(IIP)被4-vinylpyridine(单体)的copolymerization综合,ethyleneglycoldimethacrylate(cross-linker)和2,2-azobis-isobutyronitrile(开始者)面对Cd2+和quinaldic酸(complexing代理人)。IIP和空白的聚合物的吸附能力分别地是45.0和6.2mgg1,这被发现。为不同二进制混合的印的聚合物的相对选择系数也是计算的。比作非印的聚合物(捏),IIP为Cd(II)有更高的选择。IIP被使用一个简单的批抽取过程从水样品为镉抽取用作吸着剂。从IIP的Cd2+抽取和它的恢复上的不同参数的效果被使用试验性的设计方法论评估并且优化。优化吸附/解吸附作用过程被申请从真实的水样品的镉移动。获得的恢复证明这IIP能从水样品被用于踪迹镉离子的移动。

  • 标签: 印迹聚合物 吸附能力 实验设计 除镉 水样 优化
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  • 简介:ThepreparationofconductingPPQfilmwasfirstreportedinthepreviouspaper.Itisveryinterestingthatthisfilmishighlysensitivetomoistureinair.ThehydrationanddehydrationofthefilmareaccompaniedbychangenotonlyincolorbutalsoinconductivityandUV-visiblespectrum.TheconductingPPQisreducedtoPPQandlosesitsconductivityafterbeingsoakedinwater.

  • 标签: POLYPHENYLQUINOXALINE ClO4- COMPLEX Electrical CONDUCTIVITY WATER
  • 简介:Poly(β-carboxyethylmethylsiloxane)-LiClO4andpoly(β-alkoxylethylmethylsiloxane)-LiClO4crosslinkedfllmshavebeenprepared.Theionicconductivityofthefilmsdependsonthepolymerspecies,concentrationoflithiumperchlorate,temperatureandcontentofcrosslinkingagent.Theeffectofhighpolarorganicsolvent1,4-butyrolactoneontheionicconductivityandmechanicalpropertiesofpoly(β-carhoxyethylmethylsiloxane)-LiClO4systemwasalsoinvestignied.

  • 标签: IONIC conductivity: Poly(β-alkoxycarbonylethylmethylsiloxane)- LITHIUM Complex 1
  • 简介:Ionicconductivityvaluesforsegmentedpolyetherpolyurethaneurea(PEUU)complexeswithLiClO4weredeterminedandvaluesashighas~1.1×10-4S·cm-1at353Kand~1.0×10-5S·cm-1at306Kwereachieved.TheionicconductivitydatawereanalyzedusingtheVTF(Vogel-Tamman-Fulcher)equationandWLF(Williams-Landel-Ferry)typeequation.Valueshavebeenestimatedforthe"apparent"activationenergiesofiontransportfromVTFequationandtheylieintherange2.70—5.53kJ·mol-1.

  • 标签: Segemented POLYETHER polyurethaneureas Complex: Solid IONIC
  • 简介:Thiscontributionreportsethylenepolymerizationbehavioroftitaniumcomplexesincorporatingbis(phenoxyimine)ligands.Sixphenoxy-imineTi(IV)complexes{6-R1-2-[CH=N(2,6-difluoro-3,5-diR2-4-R3Ph)]C6H3O}2TiCl2(1:R1=H,R2=H,R3=H;2:R1=H,R2=H,R3=4-vinylphenyl;3:R1=CH3,R2=H,R3=H;4:R1=CH3,R2=H,R3=4-vinylphenyl;5:R1=CH3,R2=F,R3=H;6:R1=CH3,R2=F,R3=4-vinylphenyl)havebeensynthesizedandevaluatedforethylenepolymerizationusingdriedMAO(simplifiedasDMAO)ascocatalyst.AnobviouscatalyticheterogeneityofCat2(Complex2/DMAO)towardsethylenepolymerizationwasobserved,whichwasillustratedbydecreasedactivity,multimodalmolecularweightdistributionandpartiallyimprovedparticlemorphologycomparingwithCat1.Moreover,Cat3exhibits'living'characteristicsintheprocessundercertainconditions(25°C,lessthan20min).Otherwise,themoderatetohighethylenepolymerizationactivityofca.105-106gPE/(molTi·h)andhighmolecularweight(Mw=105-106)ofpolyethylenecanbeobtainedbychangingtheskeletonstructureofthesecomplexes.

  • 标签: 苯氧基亚胺 乙烯聚合 助催化剂 乙烯基 苯基 超高分子量聚乙烯
  • 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.

  • 标签: 资源再利用 废水处理 1 2 4-产酸废水 大孔聚合物吸附剂
  • 简介:TiCl_4/MgCl_2/claycompoundcatalystwaspreparedbychemicalreaction.Exfoliatedpolypropylene(PP)/claynanocompositesweresynthesizedbyinsitupolymerizationwiththiscompoundcatalyst.Effectsofpolymerizationtemperature,polymerizationtime,propylenepressure,solventconsumptionandpre-treattimeofcatalystoncatalystactivityandcatalyticstereospecificitywerestudied.Underoptimalconditions,activityofthenano-compoundcatalystisabout88.3kg/(molTi·h).IsotacticityofPPobtainedinthenanocompositesisintherangeof89%-99%,anditsmeltingtemperatureisabout159℃.Theweight-averagemolecularweightofPPcanreach6.7×10~5-7.8×10~5,andthemolecularweightdistributionisbetween7.7and7.9.

  • 标签: 纳米复合催化剂 纳米复合材料 催化剂制备 原位聚合 聚丙烯 粘土
  • 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.

  • 标签: 结晶化 聚烯烃 聚甲基丙烯酸甲脂 液晶相
  • 简介:Gasphasereductionofcarbonmonoxidetoformaldehydeandethylenewasfoundinelectrochemicalcellwithaninorganicionexchangerα-Zr(HPO4)2·H2Ousedassolidproton-conductingelectrolyteatroomtemperatureandatmosphericpressure.ThetypeandamountoftheelectroreductionofCOdependonthedifferentmetalelectrodesandcurrentdensities,whichgivesalankbetweenheterogeneouscatalysisandelectrochemistry.

  • 标签: 无机离子交换剂 α-磷酸氢锆 电解还原 一氧化碳
  • 简介:Kineticsofchloride/sulfate,chloride/nitrateandnitrate/sulfateforwardexchangesandreverseexchangesatsolutionconcentrationsof1N,0.2Nand0.02Non201×7strongbaseanionexchangeresin,respectively,havebeenexaminedat25℃.Itisfoundthattheforwardandthereverseexchangeratesofthetwogivenionsatlowsolutionconcentration,respectively,underidenticalconditionscanbecontrolledbydifferentmechanisms,whilethoseathighsolutionconcentrationareallcontrolledbyparticlediffusion.Theternaryexchangeratesofsulfate/(chloride+nitrate)andnitrate/(chloride+sulfate)havealsobeenexamined.

  • 标签: 二元离子交换 硫酸根-氯离子-硝酸根离子-201×7体系 三元离子交换 动力学