三元复合材料外文文献

三元复合材料外文文献三元复合材料外文文献 Ternary hybrid material formationby twin polymerization coupledwith the bis epoxide amine stepgrowth polymerizationMatthiasBirkner Katja Schreiter Katja Trommler Andreas Seifert Stefan Spange Technische Universit at Chemnitz Polymer Chemistry 09107Chemnitz Germanya rt ic le in foArticle history Received2FebruaryxxReceived inrevised form31MayxxAepted7JunexxAvailable online8JunexxKeywords Twin polymerizationEpoxideamine polymerizationHybrid materiala bs tr ac tHomogeneoushybrid materialsposed ofphenolic resins crosslinked polydialkylsiloxanemoietieswith linearepoxide amine positeshave beensynthesized bytwin polymerization of2 3 amino n propyl 2 methyl 4H 1 3 2 benzodioxasiline APSI bined with addition polymerization ofbisphenol A diglycidylether BADGE The ternaryformation ofthree differentpolymer structureswithinone procedurein the melt processours smoothlyas evidenced by solid state13C and29Si NMRspectroscopy The formation of insitu generatedtwin monomermoieties withhigher functionalitiesf n 2 n 2 n is the assumedaverage degreeof polymerization of thelinear chainfragments resultingintermediatelyfrom APSI and BADGE pared to the primaryreactant APSI f 2 n 1 triggers thepolysiloxanework formation A noveltype ofpolysiloxane resinis producedby thismethodology Highly thermallystable materialsare aessibleby appropriateadjustment of reaction conditionsand themolar ratio of the reactants Potential applicationsare interalia in the f i eldof glueadhesives veneers and castingresins xxElsevier Ltd All rightsreserved 1 IntroductionEpoxy resinsare animportant classof merciallyavailablepounds usedin industrialapplications foradhesives andpositematerials Mechanical andphysical propertiesof thetargetresin can be improvedby binationwith novolacs otherresin formingponents orf iller materials 1e6 The adjustmentof the mechanical properties isof greatimportance to guaranteehigh hardnesswithout brittlenessand goodprocessability duringprocessing 7e9 Twin polymerization of monomersderived fromsalicylicalcohol has been establishedas anelegant procedurefor thesyn thesis ofnanoposites dueto the formation of two differentpolymersfrom onlyone monomerwithin oneprocess stepandwithout the formation ofdisturbing byproducts 10e14 Fig 1exemplary showsthe twin polymerization of a2 methyl 2 alkyl 4H 1 3 2 benzodioxasiline derivativewhich reactsby acidcata lyzed polymerization to oligodimethylsiloxaneand aphenolic resin 13 15 The twinpolymerization ofsolely2 2 dimethyl 4H 1 3 2 benzodioxasiline doesnot deliveruseable products Both formedpolymersdo notreally undergoa hybrid material formationbecause of linearand cyclicproducts ofPDMS andportions ofphenolic resins 16 17 Hybridmaterialformation using2 2 dimethyl 4H 1 3 2 benzodioxasiline onlytakes placewhen asec ond twin monomer is used orif thealkyl groupbears anaminogroup R NH2 Then crosslinkedsilica PDMS worksareformed 13 16 Twin polymerization of amino group functionalizedtwinmonomers in the melthasbeen found asuitable toolto adheredifferentpolymers tometal ponents 15 18 Arnebold etal have shownthat the twinpolymerization of2 2 dimethyl 4H 1 3 2 benzodioxasiline can be startedwith thermolatentacids in thepresence of polymerizationof an epoxy resin 19 Combination ofepoxide amine adductformationwith ringopening polymerizationis alsouseful forintegrated polymersynthesis 20 The motivationof thisstudy isthe synergisticalbination ofthe epoxide chemistrywith twinpolymerizationof the aminofunctionalizedtwin monomer APSI APSI was used asponentfor this initial studybecause it is anticipatedthat three differentpolymer structures phenolic resin epoxy amine positesandpolydialkylsiloxane are formedwithin oneprocess As epoxyponentBADGE was used asreactant becauseof itswide useinepoxy resinproduction The predominantscenario suggestedfor Corresponding author E mail address stefan spange chemie tu chemnitz de S Spange Contents listsavailable atScienceDirectPolymerjournal homepage elsevier locate polymerdx doi 10 1016 j polymer xx 06 0150032 3861 xxElsevier Ltd All rightsreserved Polymer121 xx 38e45the1 2stoichiometry isdepicted in Fig 2a andthat for1 1stoi chiometry in Fig 2b Aording tothe establishedepoxide aminereaction it isex pected that APSI reactswith theepoxide ringin theway that alinear EP block isformed the molecular structure ofEP isdef ined inFig 2a In thecase thattwo equivalentsof APSI each of themcontains oneprimary aminogroup react quantitativelywith bothepoxidegroups of BADGE a noveltwin monomercould beformedin situwhich consistsof twotwin polymerizable moietiesbeinglinked covalentlytogether by the EP block asdemonstrated inFig 2a Then the formerfunctionality of the APSImonomer withf 2of thedimethylsiloxane moietyis duplicated Thus the insitugenerated twinmonomer APSI 2 EP isexpected toundergocrosslinking duringtwin polymerization In thecase of the1 1stoichimetry thecrosslinking reactionshould theoreticallyourmore readilywith increasingconversion becausethen theoverallfunctionality f 2 n increasesrapidly as function ofdegree ofpolymerizationn The objectiveof thisstudy isto prove the feasibilityof thisconceptionfor productionof novelpolydimethylsiloxane phenolicresin interperatingworks However itisexpected thatnewlyformed hydroxyl groups of the generatedEPblockcan reactinmany wayswith functionalgroups ofboth reactantsas knownfromliterature 21e23 Thus transesterif i cation reactions with APSIandring openingreactionswithepoxide rings are possible Further more both reactionscenarios ofFig 2can betake placesimulta neously Therefore thisinitialstudy isfocused oninf luence ofpositionof reactant mixture APSIandBADGE on themolec ularstructureformation Both ponentsare polymerizedin melt without additionalcatalysttoguaranteea cleanprocess useful forfuture applicationsinvarnish processingor gluing The molecularstructure formationsof the novelhybrid materialswere studiedby solidstate13C and29Si NMRspectroscopy and the morphologyof theproducts wasexaminedby electronmicroscopy Reaction processesin melt wereinvestigated bydifferential scanningcalorimetry DSC measure ments tooptimize theprocess parameters 2 Experimental section2 1 Materials andmethodsThe establishedtwinmonomer 2 3 Amino n propyl 2 methyl 4H 1 3 2 benzodioxa silin wassynthesized aording tothe literature 24 BisphenoleAedigylcidylether waspurchasedfrom SigmaAldrich andwasused as received 1H 13C 1H and29Si 1H NMR spectrafor allpounds wererecordedin CDCl3on aBruker Avance DRX250 250 163and49 7MHz respectively operating atroom temperature Chemicalshifts d are reportedin partsper millionand referencedwith theresidualundeuterated solvent Solid state NMR spectrawere collectedat9 4T ona BrukerAvance400spectrometer equippedwith doubletuned probescapableof MAS magic anglespinning 13Ce 1H CP MAS NMRspectra weremeasured at100 6MHz in3 2mm standardzirconiumoxide rotors BRUKER spinning at15kHz Cross polar ization witha contacttime of3ms wasused toenhance thesensitivity The recycledelay was6s Spectra werereferencedexternally to tetramethylsilane TMS as well as toadamantane assecondary standard 38 48ppm for13C 29Sie 1H CP MAS NMRFig 1 Assumed twinpolymerizationofa2 methyl 2 alkyl 4H 1 3 2 benzodi oxa sil ine derivative Fig 2 a andb Suggested grossreactions of BADGE withAPSI asfunction ofstoi chiometric equivalents1 2 2a and1 1 2b and withoutside reactionsof theEP block M Birkner etal Polymer121 xx 38e4539spectroscopy was performed at79 5MHz using3 2mm rotorsspinningat12kHz The contacttimewas3ms and the recycledelay6s Shifts werereferenced externallytotetramethylsilane 0ppm with the secondarystandardbeing tetrakis trimethylsilyl silane 9 8 135 2ppm All spectrawere collectedwith1H decouplingusinga TPPMpulse sequence The DSCmeasurements wereperformed bya DSC1 MettlerToledo in40m laluminum panand aN2 f low of50ml min TGAFig 3 DSC of APSI blue BADGE green and amixture ofboth monomers black 20e300 C 10K min 50mL min N2 with theonset temperaturesof theprocesses T endo melting T exo1 reaction of amine withepoxide T exo2 polymerization For interpretationof thereferences tocolour inthis f i gurelegend the readeris referred to thewebversion of this article Table1Overview of all polymerizationexperiments of BADGE and APSI withvariation ofreaction time temperature ratio ofmonomers andresiduals sa salicylic alcohol pr phenolic resin das dialkylsiloxane Sample Molarratio mol BADGE APSIReaction temperature C time h Extractable residuals wt Residuals11 280 159 5sa21 2100 140 1sa31 2120 133 0sa41 2140 13 8sa51 2160 15 1sa61 2180 14 1sa71 2220 1 1 9sa81 5 1140 145 8sa BADGE1 291 1140 114 1sa101 4140 170 8sa pr das1 4 4111 6140 191 5sa pr das1 1 5 1 5121 2140 61 1sa131 1220 11 0sa140 1220 223 9saFig 4 1H NMRspectra ofdifferent molar ratios of BADGE and APSI left 1 1 right 1 2 Solvent toluene T 110 C Corresponding timeconversion plotsare shownin theSI M Birkner etal Polymer121 xx 38e4540measurements wereperformed bya NetzschTG209F1 Light weight Structuresand PolymerTechnology TU Chemnitz Thesamples weremeasured under air andhelium atmosphere with aheatingrate of10K min from30to800 C Electron microscopicimages weretaken byan instrumentfromtype NovaNanoSEM200of FEICompany aftersputtering withplatinum Laboratory ofSolid SurfacesAnalysis TU Chemnitz operated at10kV 2 2 General procedureIna typicalreaction for the synthesis BADGE and APSI weremixedin aTef lon reaction vesselunder constantstirring withamagic stirringbar andheated tothe required reaction tempera ture Mostlyafter15min themixturebeeshighlyviscousandnomore stirringwas possibleandthe reaction was conducted for1h 3 Results anddiscussionReactivity studiesof thereactant binationAPSI withBADGEhave beenperformed bydifferential scanningcalorimetry DSC measurements Fig 3 A mixture of equalquantities of APSI andBADGEmelts at45 C resultingin ahomogeneous liquidmeltwhich undergoespolymerization triggeredby heat At45 C theliquidmixture can be handledwithout evidentpolymerization foratleast15min The DSCthermograms of the individualmonomers show anendothermic meltingsignal forBADGE and an exothermicpoly merization signalwith an onset temperatureof191 C forAPSI Amixture ofboth monomersshows twoexothermic signalsin theDSCthermogram The fi rstone withanonsettemperature at81 Cis probablycaused bythe reaction of theamino functionwithepoxide groups while thesecond signal is related tothe twinpolymerization of APSI 25 The anticipatedpolymerization peakisshifted tolower temperatureswhich mayresult from a catalyticeffectof theformed hydroxylgroups during the epoxyresinformation Fig 5 Images ofmonolithic samples synthesized from BADGE and APSI witha molarratio of1 2at differenttemperatures samples1e7in Table1 Fig 6 Left 13C 1H CP MAS solidstate NMRspectra andliquid13C NMRofBADGE and APSIin CDCl3 Right 29Si 1H CP MAS solidstate NMRspectra ofa non extracted sample4 homo polymerized APSIandthemonomers I A I B signals fromBADGE havebeenfound in thehybrid material II A II B signals ofphenolic resinfrom thepolymerizationof APSI III signals of the closedepoxide ring not foundin thehybrid material Fig 7 29Si 1H CP MAS solidstate NMRspectra ofmonolith materialssynthesizedusing differentmonomer ratiosofBADGE and APSI M Birkner etal Polymer121 xx 38e4541Time dependent1H NMRspectroscopy experimentswereexecuted intoluene assolvent toprovethemolecular structureformationin thefirst stageofreactionourring in the temperatureintervalup to110 C The reaction between BADGEandAPSIwas performedin boilingtolueneuntil no further changesin the1H NMRspectra could beobserved detailed informationsee supportinginformation Figs 1and2 The1H NMR experiments showedfor bothmolar ratios1 1and1 2 BADGE APSI a signif i cantdecrease of the signal at3 4ppm of the epoxyring If APSIisusedin excess the signalpletelyvanishes after3h The1H NMRsignalisattributed tothesingle hydrogenatom of the glycidylgroup which is anindi cation that all epoxy ringsareopened Also the1H NMRsignals ataround4ppm and3 8ppm broadenover timewhich displaysthepolymerization byreaction of amine and epoxide The1H NMRsignal of thetwo hydrogenatoms of the methylenebridge betweenphenolicgroup andsilicon of APSI arefound at4 9ppm whilethesame signals of thestarting materialsalicylic alcohol sa can befound at4 8ppm With increasingreaction timethe content offormed saincreases see Figs 1and2SI This mayresult from thereaction ofhydroxylgroups which aregenerated duringthe ringopeningreaction with the APSI moiety A transesterif i cationreac tionbetweenOH andAPSIis possibleand sais releasedin thesolution If the molarratiois1 1 all signalsoriginated fromSieOeCH2vanish and only sais obtained With adouble ratioofAPSI onlythe halfreacts tosa andthe excessofAPSIis stillintact Nevertheless the silicon work is stillbuild proven bythe signalsof the SieCH3protons thatare shiftedupf i eld to 0 1ppm after1h 26 Therefore the resultingpolymer has a workand notalinear structurefrom stepgrowth polymerizationofamine andepoxy function No phenolic resin couldbe obtainedby polymeri zation insolution at110 C That resultis pletelydifferentpared tothose offollowing experimentscarried outin melt Polymerization experimentsofAPSIin binationwithBADGEin themeltwerecarried outin atemperature rangefrom80 C to220 C Monolithic samplesare obtainedin aPTFE Tef lon reac tion vesselofareaction inmeltwithvariation ofthemolarratioand reaction temperature Fig 5 The experimentsand sampledescriptionare summarizedin Table1 To provethe connectivityofthe work Soxhlet extractionwithdichloromethane 48h wasconductedwhich deliverssolublefractions thatcan beassigned tolow molecularweight productsandconsiderable amountof sa The latterone isbuilt bytrans esterifi cation reactionsoftheAPSI moietywith formedhydroxylgroups from the epoxyring openingreaction The monolithssyn thesized atlower temperaturesor byuseofan excessof onemonomerhave ahigher extractablecontent whichmainly consistsofsa The extractablesa portionis signifi cantlydecreased whenT 140 C isemployed whichindicates thatformed sais thenpolymerizedto phenolic resin Molecular structureformation ofthe non extracted sample4 reaction T 140 C was investigatedby solidstate13C and29SiNMR experimentsas shownin Fig 6 The ternaryformationofphenolic resin polydialkylsiloxanework andepoxy amine polymer canbeclearly shownby13C 1H CP MAS solidstate NMRspectroscopy Fig 6 The signalsinthe areasof II A andII Bare typicalfor o o ando p linked phenolicresinstructures 27 28 An intensesignal at0ppm ofmethylFig 9 SEM imagesof monolithswith different molarratiosofBADGEandAPSIat100 top and20000 fold magnifi cation bottom samples8 4and11 Fig 8 Images ofmonolithic samplessynthesized fromBADGEandAPSI with differentmolarratios at140 C samples8 9 4 10and11in Table1 M Birkner etal Polymer121 xx 38e4542groups aswell asthe signalsfromtheother alkylchain carbonatomsfoundin the rangeof5e44ppm indicatesthe incorporationofpolydialkylsiloxane inthework 15 In parison to homo polymerized APSI red spectrum ofFig 6 the solidstate13C spectrumofthe monolithic sample4shows additionalsignals at144ppm IA and at69ppm I B whichcan beassigned asthe carbonatoms4and3fromBADGE greenspectrum No signalsof unopenedepoxyrings signals1and2ofBADGE area IIIin Fig 4 are observedinthehybrid material Therefore a pletereactionofamineandepoxy groupstookplace It issuggested thattheformationofthephenolicresinconsec utively takesplace afterpolysiloxane formationinthemelt atT 167 C bypolycondensation ofthe releasedsa whichisencapsulated within the polysiloxanework It isalso possiblethata portionof releasedsa doesreact withintact APSItwinmonomer moieties However then watershould beformed asbyproductwhich canreact withthe Si O C bondsoftheAPSImonomer The D2signalofthe BADGE APSI ternaryhybrid materialfoundat 19ppm inthe29Si 1H CP MAS solidstateNMRspectra isshifteddownf i eld inparisontothe polydialkysiloxaneof pureAPSI hybridmaterial 22ppm The signal at 22ppm istypicalfor poldialkylsiloxaneand veryclose tothe chemicalshift of linearD2groups fromPDMS The downfieldshifted29Si NMRsignal hintsatasuessful re action topolydialkylsiloxane Also nosignalsofunreacted mono mercanbe observedinthe29Si 1H CP MAS solidstate NMRspectrawhich impliesplete conversionofAPSIat140 C Thesmall downfieldshifted shouldercanberelated toD1signals orsmallcycles resultingfrom partialhydrolyzed poly dialkylsilox ane whichisexpected 29 Fig 10 EDX analysisoftwodifferent non extracted monoliths samples8and11 at5000 fold magnification M Birkner etal Polymer121 xx 38e4543There aresignificant differencesinthesolidstate29Si NMRspectraoftheresulting hybrid materials observedasfunctionofmonomer positionofthereactantmixture see Fig 7 In caseofthatAPSIwasusedin sixfoldexcess the29Si NMRspectrum ofthehybridmaterialis nearlyidentical to that ofthe homopoly merized APSI see Fig 6 right The situationis pletelydifferent when BADGEandAPSIare usedin equalportions Then threedifferent29Si NMRsignals areobserved which are identicalinposition pared tothatof1 2stoichiometry ofsample4 How ever the intensitiesofthenew signalsat about 10ppmand 30ppm areremarkably strongerpared tosample4 Thisresult isa clearindication thatthe siliconworkischemicallymodif iedbythereactionwith newlyformed alcoholicgroupsoriginating fromtheepoxidering openingor bywater formedfromsa polymerization The largerthe portionof epoxidegroups thestrongeristheinf luence observedinthe29Si NMRspectrumoftheresulting polysiloxanework paredto PDMSas reference The29Si NMRsignalatabout 19ppm isclearly attributedto thepolysiloxanechain whichhasaminor differentchemical sur rounding thanthat inthe pureAPSIhybridmaterial Aording toliterature terminal SiOHgroups from OSi CH3 2OH are foundat 10to 15ppm 29 The new29Si NMRsignalat 30ppm ofsamples4and9isdiff icult toassign becausethere isno exactliterature referenceavailableto explainthis suff i ciently 30 31 However the upfieldshift resultsfrom anelectron richsurrounding ofthe siliconatoms One explanationwould bea coordinationof oxygenincreasing thecoordinationsphere oft