简介：Inhibitorhydroquinone(HQ)wasaddedtothereactionsystemtopreparepolypropylene/polystyrene(PP/PS)blendpelletswithoutPSonthesurfaceduringdiffusionandsubsequentpolymerizationofstyreneinisotacticpolypropylenepellets.TheeffectsoftheamountofHQondiametricaldistributionofPS,surfacemorphologyofthepelletsandphasemorphologyinsidetheblendpelletswereinvestigated.

简介：摘要：以小试试验为基础，在连续法聚丙烯中试装置上，应用釜内聚合技术，合成高溶体强度的可发性聚丙烯（EPP）进行了两吨级中试研究，并考察装置能否平稳运行，中试产品指标是否能达到预期要求，根据环管淤浆聚合工艺特点，优化完善聚合工艺条件，为工业化试生产提供理论和实验依据，是本次试验的主要目的，对该项技术的放大工业化应用至关重要，对于EPP新产品的开发是必不可少的环节。

简介：Thedynamicmechanicalpropertiesofwoodpowder/polypropylenecompositeswithdifferentwoodcontenttreatedanduntreatedwiththecompatibilizerhavebeenstudied.Ithasbeenfoundthatadditionofwoodpowdersandthecompatibilizercanbothimprovetheviscoelasticityofcomposites.Glasstransitiontemperature(Tg)ofappropriatewoodpowder-filledcompositesdecreased.Thevalueforthestoragemodulus(G')increasedgraduallywithincreasingwoodpowdercontent.Theadditionofthecompatibiliz...

简介：Syntheticfibersmadefromnylonorpolypropylenehavegainedapplicationwhenlooseandwovenintogeotextileformalthoughnoinformationonthematrix’smechanicalperformanceisobtainedsothatmoreunderstandingoftheirstructuralcontributiontoresistcrackingcanbedetermined.Thispaperpresentstheresultsofanexperimentalinvestigationtodeterminetheperformancecharacteristicsofconcretereinforcedwithapolypropylenestructuralfiber.Inthisinvestigation“Fibermesh”brandoffibersmanufacturedbySLConcreteSystem,Tennessee,USAandmarketedbyM/SMillenniumBuildingSystem,Inc.,Ban-galore,Indiaareused.Thelengthsofthefibersusedwere24mm.Fiberdosagesusedwere0.9,1.8,2.7kg/m3.Atotalofthreemixtures,oneforeachfiberdosageweremade.Astandardslumpconetestwasconductedonthefreshconcretemixwithandwithoutfiberstodeterminetheworkabilityofthemix.Thetestprogramincludedtheevaluationofhardenedconcretepropertiessuchascompressive,splittensile,modulusofruptureandflexuralstrengths.Theincreaseincompressivestrengthisabout36.25%,26.20%,and23.75%respectivelythatofplainconcrete.Thisincreaseinstrengthwasdirectlyproportionaltoamountoffiberspresentinthemix.TheincreaseinflexuralstrengthforMixesI~IIIisabout21%,16.6%,and23%respectivelythatofplainconcretespecimens.Anexperimentalinvestigationwasalsomadetostudythebehaviorsofreinforcedfibersconcretebeams(withlongitudinalreinforcements)undertwo-pointloading.Thedeflectionandcrackpatternswerealsostudied.Theimprovementsinstrengthandductilitycharacteristicswerediscussed.

简介：PP/claycompositeswithdifferentdispersions,namely,exfoliateddispersion,intercalateddispersionandagglomeratesandpanicle-likedispersion,werepreparedbydirectmeltintercalationorcompounding.TheeffectofclaydispersiononthecrystallizationandmorphologyofPPwasinvestigatedviaPLM,SAXSandDSC.Experimentalresultsshowthatexfoliatedclaylayersaremuchmoreefficientthanintercalatedclayandagglomeratesofclayinservingasnucleationagentduetothenano-scaledispersionofclay,resultinginadramaticdecreaseincrystalsize(lamellarthicknessandspherulites)andanincreaseofcrystallizationtemperatureandcrystallizationrate.Ontheotherhand,adecreaseofmeltingtemperatureandcrystallinitywasalsoobservedinPP/claycompositeswithexfoliateddispersion,duetothestronginteractionbetweenPPandclay.Comparedwithexfoliatedclaylayers,theintercalatedclaylayershavealessimportanteffectonthecrystallizationandcrystalmorphology.Noeffectisseenforsampleswithagglomeratesandpanicle-likedispersion,inregardtomeltingtemperature,crystallizationtemperature,crystalthicknessandcrystallinity.

简介：在聚丙烯(PP)改进硅石的分散矩阵并且避免抗氧化剂的物理损失，有表面(SG-PAMAM)上的dendricpolyamidoamines的nanosilica被使用分叉的方法综合。然后使nanosilica不能调动的抗氧化剂(SG-PAMAM-AO)被从2,6-di-tert-butyl-4-phenol(AO)被导出的grafting2,6-di-tert-butyl-4-aminophenol准备。SG-PAMAM-AO被增加进PP由融化混合学习变老的性质。PP/SG-PAMAM-AO和PP/AO混合物的氧化正式就职时间被测量。SG-PAMAM-AO的抗氧化剂性质比AO的优异，这被发现。根据在相片热的老化前后的羰基吸收的变化，PP/SG-PAMAM-AO的相片热的氧化稳定性比PP，PP/SG-PAMAM和PP/AO的高得多。

简介：Thepolypropylene(PP)nanocompositesfilledwithpretreatedhalloysitenanotubes(HNTs)werepreparedbythemelt-blendingmethod.Beforefilling,theas-receivedHNTspowderwasatfirstpurifiedandthenmodified.ThecharacterizationtestsshowedthatthepurifiedHNTshadlessimpurityandmoreuniformporesizedistributionandthesurfacehydrophobicityofthemodifiedHNTswasobviouslyimproved.ThemechanicalandtribologicalpropertiesofthePP/HNTsnanocompositeswereextensivelyinvestigated.Theresultsshowedthatthetensile,bendingandnotchedimpactstrengthofthePP/HNTsnanocompositeswassomewhatimproved,butthewearresistanceofthePP/HNTsnanocompositeswasobviouslyenhanced.

简介：Thesurfaceofpolypropylene(PP)membranewasmodifiedbylowtemperatureplasmawithammonia.Theeffectofexposuretimewasinvestigatedbymeansofcontactanglemeasurement.Theresultsshowthatlowtemperatureammoniaplcsmatreatmentcanenhanceitshydrophilicity.Chinesehamsterovary(CHO)cellsattachmentonthemodifiedmembranewasenhancedandthegrowthrateonthemembranewasfasterthanunmodifiedone.

简介：铝次磷酸盐(AHP)的效果作为火焰retardancy和包含铵polyphosphate(应用软件)和triazine的膨胀火焰retardant聚丙烯composites(PP/IFR)的热降级行为上的一个synergistic代理人，起泡沫嘉鱼之类的代理人(CFA)被限制氧索引(LOI)调查，UL-94测量，thermogravimetric分析(TGA)，锥热量计测试(锥)，扫描电子显微镜学(SEM)和X光检查光电子光谱学(XPS)。有AHP的IFR的联合展出了明显的synergistic效果并且为PP矩阵提高了火焰retardant效率，这被发现。有0.8公里的厚度的标本能递给UL-94评价的V-0，LOI价值基于24wt%，和AHP/IFR的最佳团部分的火焰retardant装载的总数到达33.5%是1:6。TGA数据表明AHP能改变IFR和PP/IFR系统的降级行为，在高温度提高IFR和PP/IFR系统的热稳定性并且支持字符残余形成。锥结果表明IFR/AHP混合能高效地减少PP的燃烧参数，例如热版本率(HRR)，全部的热版本(THR)，烟生产率(SPR)等等。字符残余的词法结构证明AHP在烧期间具有材料表面上的更紧缩、同类的字符层的形成的利益。XPS的分析显示AHP可以在材料表面上支持足够的字符的形成并且改进火焰retardant性质。

简介：Theeffectofwoodspecies(ChinesefirandPoplar),woodfibercontent(10%,25%,40%)andwoodfibersizes(16to32mesh,32-65mesh,above65mesh)onthepropertiesofthewoodfiber-Polypropylenecompositeswerestudiedinthispaper.Theresultsindicatethattheeffectofwoodfibercontentandsizeincompositeweremoreimportantthanthatofchosenwoodspecies.Comparedwithpolypropylenewithoutwoodfiber,theflexuralstrengthofthecompositesincreasedwhenaddingwoodfiberintopolypr...

简介：Theeffectofvinylacetate(VA)contentinethylenevinylacetate(EVA)copolymeronthemechanicalpropertiesofpolypropylenewasinvestigated.ThreedifferentEVAcopolymerswithconcentrationsof3wt%,6wt%,9wt%,12wt%and15wt%,wereblendedtopolypropylene.Themechanicalpropertiessuchasyieldandtensilestrengths,elasticmodulus,Izodimpactstrength,hardnessandmeltflowindexoftheblendswereinvestigated.Relationshipbetweentypeofvinylacetateandconcentrations,mechanical,MFIandmorphologicalpropertieswereexplored.

简介：Surfacemodificationofpolypropylenemembranebyargon(Ar)plasma-inducedgraftpolymerizationwithhydrophilicn,onomer[acrylicacid(AA)inthiswork]wasinvestigated.ItwasfoundthatboththedistanceofthemembranefromtheArplasmacenterandtheplasmapowerhadastronginfluenceonthesurfacemodification,hydrophilicityandgraftyield(GY)ofthetreatedmembrane.Resultssuggestthatremoteplasmatreatmentwithapropersampleposition,plasmapowerandgraftpolymerizationleadstoamembranesurfacewithnotonlylessdamage,bntalsomorepermanenthydrophilicity,thandirectplasmatreatmentdoes.Byanalyzingthemorphologyandthechemicalcompositionofthemembranesurfacebyscanningelectronmicroscopy(SEM)andX-rayphotoelectronspectroscopy(XPS),aswellasFouriertransforminfraredattenuatedtotalreflectionspectroscopy(FTIR-ATR)respectively,apossiblemechanismwastentativelyrevealed.

简介：Astudyconcerningtheeffectofvibrationonthecrystalstructureandmorphologyforisotacticpolypropylene(iPP)wasconducted.Thecrystallitesize.crystalstructureandcrystallinityofiPPunderorwithoutvibrationtreatmentwereinvestigatedbymeansofdifferentialscanningcalorimetry(DSC)andwideangleX-raydiffraction(WAXD).Theresultsrevealthatthecrystallinityofthevibratedsamplesdecreasesatahighcoolingrate,butitremainsconstantatalowcoolingratebecauseofthechainrelaxationofiPP.Ithasbeenfoundthatvibrationobviouslyincreasesthecontentofβ-formofcrystalphaseandtheamountofβ-crystalmainlydependsonthevibrationamplitude.

简介：Themechanicalpropertiesofwoodpowder/polypropy!enecompositeswithdifferentwoodparticlesizesandwoodspecieshavebeenstudied.AllofthewoodparticiesizesincreasedtheE-modulusofthecomposites.Tensiletestsshowedthatwoodpartidesizeshadanegativeeffectontheelongationatbreakandthetensilestrengthofthecompositeshasbeenimprovedwhenwoodparticlesizeswerebe(ow150μm(below100mesh).Fortheimpacttests,thewoodpartidesizeshadanegativeeffect,buttheMDFf...

简介：Photo-oxidativedegradationofpolypropylene/claymultifilamentyarnscontainingdifferentamountsofclaywasinvestigated.Thesesamplesandpurepolypropylene(PP)multifilametnswereexposedtolongwavelengthradiations(λ>300nm)underatmosphericconditionofconstanttemperatureandrelativehumidity.Thephoto-oxidativestabilitywasstudiedusingFTIRspectroscopy,tensiletestingandmicroscopy.TheresultsindicatethattheadditionofclayparticlesdecreasesthestabilityofPP/claycompositestophoto-oxidativedegradationaccordingtocomparisonwithpurePP.FromFTIRstudyandtensileproperties,itwasalsofoundthatthemultifilamentswithhigherclayloadingrevealsafasterlossofmechanicalproperties,higherphoto-oxidativeproductformationandmorereductionintheinductiontimeofphotooxidation.Moreover,thecrackformationonsurfaceofirradiatedfilamentscorrespondswelltotheconclusionsintensilepropertiesandFTIRcharacterization.

简介：Polymerizationofacrylonitrile(AN)inaqueousnitricacidinitiatedbypolypropylene-basedpolyamidoxime(PPAO)-thiourea(TU)combinationhasbeeninvestigated.Theoverallrateofpolymerization(R_p)undertheconditionsof[TU]/[PPAO]<0.5molarratioisThemolecularweightsofthepolymerswerefoundtobeinverselyproportionalto3/2-powerofnitricacidconcentrationand1-powerofthioureaconcentration.Inaddition,itisindependentwiththeconcentrationsofmonomerandPPAO,anddecreaseswithincreasingtemperature.Onthebasisoftheseexperimentalresults,acoordination-protontransfermechanismfortheinitiationwasproposedanddiscussed.

简介：

简介：在我们的当前的工作，在有起核心作用的代理人的isotactic聚丙烯(iPP)的水晶的生长上的shear温度的效果被调查借助于在situ二维的宽角度的X光检查衍射(2D-WAXD)。在低砍温度，面向的先锋是的形成的砍导致难由于分子的链的弱活动性放松回到随机的卷的状态。因此，很多的面向的晶体被砍导致导致面向的先锋，当水晶极大地被压抑时。作为shear温度增加，面向的水晶逐渐地与水晶的减少一起增加。这被推出水晶的内容在增加到的shear温度(最大值)在静止结晶化发现的价值在结晶化动力学上的流动的加速的效果哪个完全被擦掉几乎与那一样。我们的工作在结构和iPP的性质操作在调整水晶并且这样表明它的意义。

简介：Theconformationalanddynamicpropertiesofpolypropylene(PP)forbothpuremeltsandblendswithdifferentchaintacticitywereinvestigatedbyMonteCarlosimulationofisotactic(iPP),atactic(aPP)andsyndiotactic(sPP)polypropylenes.Thesimulationofcoarse-grainedPPmodelswasperformedonahighcoordinationlatticeincorporatingshort-andlong-rangeintramolecularinteractionsfromtherotationalisomericstate(RIS)modelandLennard-Jones(LJ)potentialfunctionofpropanepairs,respectively.ThedynamicsofchainsinbinaryPP/PPmixturewereinvestigatedwiththecompositionofC150H302withdifferentchaintaciticity.ThediffusionratesofPPwithdifferentstereochemistryaregenerallyintheorderas:iPP>aPP>>sPP.ForPP/PPblendswith50:50wt%binarymixtures,immiscibilitywasobservedwhensPPwasintroducedintothemixtures.ThediffusionrateofiPPandaPPbecamesloweraftermixing,whilesPPdiffusessignificantlyfasterinthebinarymixtures.ThemobilityofPPchainsdependsonbothintramolecular(molecularsizeandchainstiffness)andintermolecular(chainpacking)interactions.TheeffectofintramolecularcontributionisgreaterthanthatofintermolecularcontributionforiPPandaPPchainsinbinarymixtures.ForsPPchain,intermolecularinteractionhasgreaterinfluenceonthedynamicsthanintramolecularcontribution.

简介：Theaqueouspolymerizationofmethylmethacrylateintiatedbycopperpolypropylene-basedpoly(oxime-imidodiacetate)(P-Cu)-sodiumsulfitesystemhasbeeninvestigated.Theoverallrateofpolymerization(Rp)wasfoundtobeRp=5.8×10^12e^-84.1KJ/RT[MMA]^1.4[P-Cu]^0[Na2SO3]^0.50Amechanismof“coordination-protontransfer”fortheproductionofinitiatingspecieswasproposedanddiscussed.