学科分类
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17 个结果
  • 简介:AdsorptionequilibriumexperimentsofphenolontheNKAIIresinareseparatelyconductedinthepresenceandabsenceofultrasoundatambienttemperature.Theisothermofphenolonthepolymeradsorbentinthepresenceofultrasonicfieldisfirstlyreported.Resultsindicatedthattheisothermofphenoldeterminedinthepresenceofultrasoundislowerthanthatintheabsenceofultrasound.Inaddition,experimentsalsoshowthattheuseofultrasoundtotheadsorptionsystemofthephenolaqueoussolutionandNKAⅡresincouldcausetherisingofthetemperatureofthesystemintheorderof6^-C.TheeffectofultrasoundontheisothermofthephenolontheNKAⅡresinmostlyascribestothethermaleffectandthenon-thermaleffectofultrasonicfield.andtheroleofthelaterisgreaterthanthatoftheformer.

  • 标签: 树脂 超声波 吸收
  • 简介:Newacetylenemonomers,6-{[(1-naphthylethynyl-4-phenyl)carbonyl]oxy}-l-phenyl-l-hexyne(1),2,5-diethynylthiophene(3),and4,4′-diethynylbiphenyl(6)weresynthesized.Homopolymerizationof1andcopolycyclotrimerizationsof3and6with1-heptyneandl-octynehavebeenachievedwithWCI6-andTaC15-Ph4Sncatalysts,respectively,givingsolublelineardisubstitutedpolyacetylene(2)andhyperbranchedpolyarylenes(5and8)withhighmolecularweights(upto1.2×105)inhighyields(upto98%).ThestructuresandpropertiesofthepolymersarecharacterizedandevaluatedbyIR,NMR,TGA,UV,photoluminescence(PL),andelectroluminescence(EL)analyses.Allthepolymerspossesshighthermalstabilityandemitstrongbluelightuponphotoexcitation.Theintensityoftheemittedlightisgreaterthanthatofpoly(1-phenyl-1-octyne),awell-knownhighlyluminescentdisubstitutedpolyacetylene.Littleaggregation-inducedredshiftinthePLwasobservedinthethinfilmsofthepolymers.Byconstructingamulti-layerELdevice,highELquantumyield(0.18%)hasbeenachievedin2,whicharethebestresultsforsubstitutedpolyacetylenesattainablesofar.

  • 标签: DISUBSTITUTED polyacetylene HYPERBRANCHED polyarylene LIGHT EMISSION
  • 简介:Thestraininducedcrystallizationbehaviourinpolyimidefrom1,4-bis(3’,4’-dicarboxyphenoxy)benzeneand4,4’-oxydianiline(PEI-E)hasbeeninvestigatedbyWAXD,DSCandFTIR.TheresultsobtainedshowthatcrystallizationinPEI-Edidtakeplacejustaftertensileyielding.Meanwhile,theeffectofstraininducedcrystallizationonthethermomechanicalpropertieswasstudiedbyDMAandTMA,theresultsofwhichindicatethatthecrystallizationandhotstretchinghaveacertaininfluenceonthedynamicmechanicalproperties,suchasweakeningtheβrelaxationanddecreasingtheglasstransitiontemperature.TheTMAresultsconfirmtheshiftingofglasstransitiontemperaturetolowertemperatureregionafterhotstretching.ThisphenomenoncouldbewellexplainedbytheeffectofresidualstressaccordingtoEyring’stheory.

  • 标签: POLYIMIDE Strain induced CRYSTALLIZATION Thermal MECHANICAL
  • 简介:Carboranebisphenolnovolacs(3and4)weresynthesizedinthepresenceofacidcatalystfromcarboranebisphenols(5and6)andformaldehyde.Furtherepoxidizationofcarboranebisphenolnovolacswithepichlorohydringavecarboranebisphenolepoxynovolacs(1and2).Themolecularweightandepoxyvalueofobtainedresinsweredeterminedusingthemolecularweightoftheirprecursors.Theepoxyvaluesof1and2were0.48and0.52respectively,higherthanthemaximumtheoreticalepoxyvalue(0.45)ofdifunctionalcarboranebisphenolepoxyresins.FTIRandNMRwereutilizedtocharacterize1and2.ThecuringbehaviorswerealsostudiedbyDSCandtheoptimizedcuringconditionswereobtained.TGAanalysisindicatedthatcarboranemoietycouldshielditsadjacentorganicstructuresagainstinitialdecomposition.Ontheotherhand,B―Honcarboranecagecouldreactwithoxygentoformathree-dimensionalnetworklinkedbyB―O―BandB―Cbonds,whichfurtherblockedthemovementofformedradicalsandthusthedegradationprocesswasinhibited.

  • 标签: CARBORANE Epoxy novolacs Thermal stability
  • 简介:用树脂分的在结构上多样的bispropargyl醚,quinol,4,4-dihydroxy联本基,bisphenol--A,4,4-dihydroxydiphenyl酉同类,4,4-dihydroxydiphenylsulphone,trimethylindanebisphenol和tetramethylspirobiindanebisphenol被使用阶段转移准备催化剂。综合材料独立在鼹鼠比率(0.5:0.5)与4,4-bismaleimidodiphenyl甲烷(BMIM)被混合。材料热地被治好,结构的描述和这些cross-linked材料的热性质用Fourier变换被调查红外线(FTIR)分光光度计和thermogravimetric分析器(TGA)。在不同材料之中,调查polyMRPE,polyMBPEBPA和polyMSPE显示出300諟?牦的更高的发作降级温度吗?

  • 标签: 热降解动力学 结构表征 双马来酰亚胺 傅里叶变换红外光谱分析 共混物 TG-FTIR
  • 简介:(L减水乳酸)(PLLA)Poly,/pristine蛭石nanocomposites被准备由融化掺双轴的extruder,和热、机械的性质的蛭石分散状态的详细信息和蛭石的效果系统地被学习。当装载内容不超过3wt%时,结果证明在矩阵的蛭石的分散相当好。太古的蛭石能显然在nonisothermal结晶化期间改进融化结晶化温度。两结晶化时间跨度和PLLA的spherulitic尺寸由提高PLLA的主要成核在等温的结晶化状况下面与蛭石的增加的数量减少。并且增加的蛭石能也改进张力的模量和PLLA的Izod影响力量。为PLLA上的蛭石的起核心作用的效果的内在的机制被建议是在蛭石和PLLA之间的取向附生的结晶化和特定的相互作用。

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

  • 标签: 热氧老化 热稳定性 催化剂 残留物 丁烯 本体沉淀聚合
  • 简介:当他们被介绍进主要的链时,热imidizaiton上的benzimidazole单位的效果被学习poly(amic酸)(泛美航空公司)。PAA-PABZ的热imidization过程由3,3,4,4-biphenyltetracarboxylicdianhydride(BPDA)综合了,2-(4-aminophenyl)-5(6)-aminobenzimidazole(PABZ)被TGA学习,DSC,直接存储器存取,FTIR并且在situFTIR。FTIR并且在situFTIR的结果显示单位充当的benzimidazole一在里面当温度比170低时,加速泛美航空公司的热imidization到polyimide(PI)的situ催化剂?????????????????????????ㄠ?????獩瑯捡楴?????偩???h

  • 标签: 氢键相互作用 苯并咪唑 催化剂 酰胺酸 热亚胺化 单位
  • 简介:trans-1,4-polybutadiene-co-isoprene共聚物TBIR的二个系列用催化剂系统TiCl被准备<潜水艇class=“a-plus-plus”>4/MgCl2-Ali-Bu在不同反应温度的3。所有二和三个一组顺序分布,数字一般水准顺序长度和共聚物的顺序集中被计算根据<啜class=“a-plus-plus”>13C-NMR系列。温度和到到在TBIR共聚物的链片断的分发上的Ip的异戌二烯Bd的丁二烯的起始的臼齿的比率的影响被讨论。共聚物作文和热性质的关联也被评估,它便于由改变Bd内容和温度控制crystallinity和转变温度的度的理解。

  • 标签: 序列分布 异戊二烯 共聚物 丁二烯 热性能 反式
  • 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.

  • 标签: 聚碳酸亚丙酯 环氧琥珀酸 流变性能 共混物 环保型 〇PPC
  • 简介:这个工作报导杂环的functionalized聚合物的合成和描述,poly(triazole-etherimidazole)s(PTAEI)从终止dialkyne的混合物,3-(4,5二度(4-(propargyloxy)苯基)由使用按反应的-1H-imidazol-2-yl)-9-ethyl-9H-carbazole,。PTAEI被描绘并且他们的性质象溶解度那样,热,机械,photophysical和金属离子吸附被调查。这些聚合物让重量平均臼齿的群众(M<潜水艇class=“a-plus-plus”>在1910026700g/mol的范围的w),在极的aprotic溶剂展出了优秀溶解度并且由答案扔形成了低有颜色的灵活薄电影方法。他们与玻璃转变温度展出了好热稳定性(T<潜水艇class=“a-plus-plus”>在160之间的g)??????????千偓???????????????????吗??

  • 标签: 纳米复合材料 杂环聚合物 机械性能 金属离子 光物理 表征
  • 简介:ThisarticleaddressesthesynthesisoforganicallytailoredNi-Allayereddoublehydroxide(ONi-AlLDH)anditsuseinthefabricationofexfoliatedpoly(methylmethacrylate)(PMMA)nanocomposites.ThepristineNi-AlLDHwasinitiallysynthesizedbyco-precipitationmethodandsubsequentlymodifiedusingsodiumdodecylsulfatetoobtainONi-AlLDH.NanocompositesofPMMAcontainingvariousamountsofmodifiedNi-AlLDH(3wt%?7wt%)weresynthesizedviasolventblendingmethodtoinvestigatetheinfluenceofLDHcontentonthepropertiesofPMMAmatrix.SeveralcharacterizationmethodssuchasX-raydiffraction(XRD),transmissionelectronmicroscopy(TEM),Fouriertransforminfraredspectroscopy(FTIR),rheologicalanalysis,differentialscanningcalorimetry(DSC)andthermogravimetricanalysis(TGA),wereemployedtoexaminethestructural,viscoelasticandthermalpropertiesofPMMA/OLDHnanocomposites.TheresultsofXRDandTEMexaminationconfirmtheformationofpartiallyexfoliatedPMMA/OLDHnanocomposites.TheFTIRresultselucidatethatthecharacteristicbandsforbothpurePMMAandmodifiedLDHarepresentinthespectraofPMMA/OLDHnanocomposites.Rheologicalanalyseswerecarriedouttoexaminetheadhesionbetweenpolymermatrixandfillerspresentinthenanocompositesample.TheTGAdataindicatethatthePMMAnanocompositesexhibithigherthermalstabilitywhencomparedtopurePMMA.ThethermaldecompositiontemperatureofPMMA/OLDHnanocompositesincreasesby28KcomparedtothatofpurePMMAat15%weightlossasapointofreference.IncomparisonwithpurePMMA,thePMMAnanocompositecontaining7wt%LDHdemonstratesimprovedglasstransitiontemperature(Tg)ofaround3K.Theactivationenergy(Ea),reactionorders(n)andreactionmechanismofthermaldegradationofPMMA/OLDHnanocompositeswereevaluatedusingdifferentkineticmodels.WateruptakecapacityofthePMMA/OLDHnanocompositesislessthanthatofthepurePMMA.

  • 标签: 聚合物/纳米复合材料 PMMA 溶液共混法 LDH 热性能 合成
  • 简介:TheSiO2nanoparticleswerecoatedonthesurfaceofgrapheneoxide(GO)bysol-gelmethodtogettheSiO2-Gcompound.TheSiO2-GwasrestoredandoleophylicallymodifiedtopreparehydrophobicmodifiedSiO2-G(HM-SiO2-G)whichwassubsequentlyaddedtosiliconerubbermatrixtopreparetwo-componentroomtemperaturevulcanized(RTV-2)thermalconductivesiliconerubber.Themorphology,chemicalstructureanddispersityofthemodifiedgraphenewerecharacterizedwithSEM,FTIR,Raman,andXPSmethods.Inaddition,theheat-resistancebehavior,mechanicalproperties,thermalconductivity,andelectricalconductivityoftheRTV-2siliconerubberwerealsostudiedsystematically.TheresultsshowedthattheSiO2nanoparticleswerecoatedongrapheneoxidesuccessfully,andHM-SiO2-GwasuniformlydispersedinRTV-2siliconerubber.TheadditionofHM-SiO2-Gcouldeffectivelyimprovethethermalstability,mechanicalpropertiesandthermalconductivityofRTV-2siliconerubberandhadnogreatinfluenceontheelectricalinsulationperformance.

  • 标签: GRAPHENE Modification Two components ROOM temperature
  • 简介:Poly(etherurethane)s(PEU),includingPEUI15andPEUH15,werepreparedthroughchain-extensionreactionofpoly(ethyleneglycol)(PEG-1500)usingdiisocyanateasachainextender,includingisophoronediisocyanate(IPDI)andhexamethylenediisocyanate(HDI).ThesePEUswereusedtotoughenpolylactide(PLA)byphysicalandreactiveblending.Thermal,morphological,mechanicalandagingpropertiesoftheblendswereinvestigatedindetail.ThesePEUswerepartiallycompatiblewithPLA.Theelongationatbreakofthereactiveblendsinthepresenceoftriphenylphosphate(TPP)forPLAwithPEUH15orPEUI15wasmuchhigherthanthatofthephysicalblends.Theagingtestwascarriedoutat-20°Cfor50hinordertoacceleratethecrystallizationofPEUs.ThePEUsinthePLA/PEUblendsproducedcrystallizationandformednewphaseseparationwithPLA,resultinginthedeclinedtoughnessofblends.Fortunately,undertheagingcondition,althoughPEUH15inblendscouldalsoformcrystallization,thereactiveblendofPLA/PEUH15/TPP(80/20/2)hadhighertoughnessthantheotherblends.TheelongationatbreakofPLA/PEUH15/TPP(80/20/2)droppedto287%fortheagingblendfrom350%fortheoriginalblend.ThetensilestrengthandmodulusofPLA/PEUH15/TPPblenddidnotchangeobviouslybecauseofthecrystallizationofPEUH15.

  • 标签: POLYLACTIDE Poly(ethylene glycol) Poly(ether urethane) Toughness AGING
  • 简介:Blendsofpoly(3-hydroxybutyrate-co-3-hydroxyhexanoate)(PHBHHx)andpoly(butylenesuccinate-adipate)(PBSA),bothbiodegradablesemicrystallinepolyesters,werepreparedwiththeratioofPHBHHx/PBSArangingfrom80/20to20/80bymeltmixingmethod.Differentialscanningcalorimetry(DSC),thermogravimetryanalysis(TGA),dynamicmechanicalthermalanalysis(DMA),polarizingopticalmicroscopy(POM)andwideangleX-raydiffractometer(WAXD)wereusedtostudythemiscibilityandcrystallizationbehaviorofPHBHHx/PBSAblends.ExperimentalresultsindicatethatPHBHHxisimmisciblewithPBSAasshownbythealmostunchangedglasstransitiontemperatureandthebiphasicmelt.

  • 标签: 热性质 结晶行为 聚(3-羟基丁酸基-共-3-羟基己酯)聚(丁烯琥珀酸酯-己二酸) 可混和性