聚乙烯混合二氧化硅复合材料的表面引发催化乙烯聚合

Surface-initiatedcatalyticethylenepolymerizationwithinnano-channelsoforderedmesoporoussilicasforsynthesisofhybridsilicacompositescontainingcovalentlytetheredpolyethyleneLixinXua,ZhibinYea,b,*,QingzhouCuic,ZhiyongGuc,LouisMercierbaSchoolofEngineering,LaurentianUniversity,935RamseyLakeRoad,Sudbury,OntarioP3E2C6,CanadabDepartmentofChemistryandBiochemistry,LaurentianUniversity,Sudbury,OntarioP3E2C6,CanadacDepartmentofChemicalEngineering,UniversityofMassachusettsLowell,Lowell,MA01854,USAarticleinfoArticlehistory:Received18September2011Receivedinrevisedform1November2011Accepted5November2011Availableonline12November2011Keywords:OrderedmesoporoussilicaPdediiminecatalystCovalentsurface-graftingabstractAsurface-initiatedcatalyticethylenepolymerizationtechniqueissuccessfullydemonstratedhereinforthecovalentsurface-graftingofpolyethylenechainswithinnanochannelsofmesoporoussilicastogivehybridmesoporoussilica/polyethylenecompositematerials.Inthistechnique,aPd�diiminecatalyst,[(ArN]C(Me)e(Me)C]NAr)Pd(Me)(N^CMe)]þSbF�6(Ar¼2,6-(iPr)2C6H3)(1),wasfirstcovalentlyimmobilizedontotwoorderedmesoporoussilicas(SBA-15andMSU-F)containingsurface-boundacryloylfunctionalitiestorenderthemesoporoussilica-supportedchelatePd�diiminecatalysts(Pd-SBA15andPd-MSUF,respectively).Surface-initiatedethylenepolymerizationswithinmesoporesweresubsequentlycarriedoutwithPd-SBA15andPd-MSUFatanethylenepressureof400psiand5�C.Amechanisticstudyonthepolymerizationbehaviorandtheconfiningeffectsofsilicameso-structuresonpolymergrowthhasbeenundertaken.Thecovalentsurface-graftingofpolyethylenewithinsilicananochannelswasconfirmedbytheresultsfromFourier-transformedinfrared(FTIR)spectroscopy,thermogravimetricanalysis(TGA),nitrogenadsorptionedesorption,electronmicroscopy,andprotonnuclearmagneticresonance(1HNMR).Thecontentofgraftedpolyethyleneinthecompositescanbeadjustedinawiderangebyvaryingpolymerizationtime.Thisrepresentsthefirstreportonthecovalentsurfacefunctionalizationofmesoporoussilicaswithpolyethyleneviasurface-initiatedet