Structure/property relationships in methacrylate/dimethacrylate polymers for dental applications

214 Pages·2001·8.1 MB·English

by  Mehlem, Jeremy John,

STRUCTURE/PROPERTYRELATIONSHIPSIN
METHACRYLATE/DIMETHACRYLATEPOLYMERSFORDENTAL
APPLICATIONS
By
JEREMYJOHNMEHLEM
ADISSERTATIONPRESENTEDTOTHEGRADUATESCHOOL
OFTHEUNIVERSITYOFFLORIDAINPARTIALFULFILLMENT
OFTHEREQUIREMENTSFORTHEDEGREEOF
DOCTOROFPHILOSOPHY
UNIVERSITYOFFLORIDA
2001
[Thisdissertationisdedicatedtoallofthosewhogavetheirloveandsupportduringthe
writingofthedissertation,especiallymywifeKacy.]
ACKNOWLEDGMENTS
Iwouldliketothankmyadvisoranddoctoralcommittee,Dr.AnthonyBrennan,
withoutwhoseenthusiasm,knowledge,andguidancenoneofthiswouldbepossible. I
wouldalsoliketothankthemembersofthesupervisorycommitteefortheirvaluable
input:Dr.ElliotDouglas,Dr.ChristopherBatich,Dr.RonaldBaney,andDr.Kenneth
Wagener.
Icannotthankenoughallofmycolleagueswhogavethesupportand
collaborationnecessarytomakeitthroughthisonerousprocess: MarkSchwarz,Jennifer
Russo,JeanneMacdonald,Dr.LuxsameePlangsangmas,XiaomeiQian,DerekLincoln,
ArthurGavrin,JamieRhodes,LeeZhao,Dr.BrentGila,Dr.DrewAmery,BobHadba,
Dr.ChrisWidenhouse,Dr.RodrigoOrifice,Dr.JamesMarrotta,andPaulMartin. I
wouldalsoliketothankthenextgenerationofcolleaguesforbringingnewideasand
perspectivestoourdiscussions: ClaytonBohn,AdamFeinberg,WadeWilkerson,Nikhil
Kothurkar,AmyGibson,CharlesSeegert,LeslieWilson,BrianHatcher,BrendanHauser,
BryanCuevas,JoshStopek,andalltheotherstudents,faculty,andstaffthatmademy
experienceattheUniversityofFloridamemorable.
IcannotexpressenoughgratitudetoDr.JesseArnold,Dr.TomMillerandDr.
MikeZamorafortheirguidanceearlyinmycareerasagraduatestudentandtheir
continuedadviceasIgointotheworkplace.
SpecialthanksgoesouttoMs.TonyaBrevaldiforherhelpwithNMR
spectroscopyandMrs.JeanneMacdonaldforherhelpwithDSCmeasurements. Iwould
iii
alsoliketothankDr.C.RussellBowersandhisgraduatestudent,TonyZook,forallof
theirhelpmakingl29xenonNMRmeasurements. Icouldnothavecompletedthework
withouttheircollaboration.
Iwouldberemissnottorecognizetheaidthattheprogramassistantsprovide. I
wouldalsoliketothankDr.PeterIfjuforhishelpinmakingmodulusmeasurementon
ourstandardsandhisimpromptumentoringatourboardmeetings.
ImustacknowledgetheCenterfortheDevelopmentofAlternativestoDental
AmalgamattheUniversityofFlorida,especiallyMr.BenLeeinthedentalbiomaterials
laboratoryandtheNIH-NIDR(grantno.2-P50-DE09307)forfundingmyresearchand
allowingmetheopportunitytoattendandpresentmyworkatnationalconferences.
Iwouldliketothankmyparentsandfamilyforsupportingmycontinuededucation.
Last,butnotleast,Iwouldliketothankmywife,Kacy,forherloveandsupportthrough
thelastyearsofmyeducation.
IV
TABLEOFCONTENTS
page
ACKNOWLEDGMENTS
iii
LISTOFTABLES vii
LISTOFFIGURES x
ABSTRACT xiv
1 INTRODUCTION 1
2 BACKGROUND 5
HistoryofDentalRestorativeMaterials 5
ComponentsofDentalComposites 6
AreasforImprovement 8
NetworkStructure 8
Bis-GMAAnalogsandModifications 12
Monomethacrylates 16
PolymerizationShrinkage 18
AnhydridesinDentalMaterials 25
WaterAbsorption 28
MechanicalProperties 29
17QXenonNuclearMagneticResonanceSpectroscopy 32
DynamicMechanicalSpectroscopy 42
Summary 44
3 ALTERNATEDILUENTSYSTEMSFORBIS-GMAANDBIG-GMA
ANALOGS 47
RelevantBackground 47
MaterialsandMethods 52
ResultsandDiscussion 60
PhysicalProperties 60
FlexureTesting 69
FractureToughnessandTensileTesting 76
DynamicMechanicalSpectroscopy 83
ComparisonofAlternateComonomerSystemsbyWeighttoTriethyleneGlycol
Dimethacrylate 110
FlexureTesting 110
TensileStrengthandFractureToughness 115
ConclusionsandFutureWork 120
4 CHARACTERIZINGTHEHETEROGENITYOFDIMETHACRYLATE
POLYMERS 123
RelevantBackground 123
MaterialsandMethods 126
ResultsandDiscussion 131
AtomicForceMicroscopy 131
Xenon-129NMR 145
ConclusionsandFutureWork 156
5 EVALUATIONOFTHEEFFICIENCYOFTHEINCORPORATIONOFNADIC
METHYLANHYDRIDE,NORBORNENEBASEDCOMPOUNDSANDMALEIC
ANHYDRIDEINTOMETHACRYLATE-BASEDDENTALRESINS 158
RelevantBackground 158
MaterialsandMethods 161
ResultsandDiscussion 163
Conclusions 177
6 CLOSINGREMARKS 181
LISTOFREFERENCES 185
BIOGRAPHICALSKETCH 196
VI
LISTOFTABLES
Table Page
Table2.1: VolumetricshrinkagevaluesandmodulusvaluesforBis-GMAmolecules
esterifiedwithvarious-lengthaliphaticacids. ThenumbernexttoC
representsthenumberofcarbonatomsinthealiphaticchain 21
Table2.2: Mechanicalpropertiesandwatersorptionofvariousunfilleddimethacrylate
polymerswetanddry 30
Table2.3: DegreeofconversionvaluesforBis-GMA/TEGDMApolymerssystems
obtainedbyFerracane 32
Table2.4: GlasstransitiontemperatureestimatesobtainedbyWilsonandTurner 44
Table3.1: Materialsused 53
Table3.2: Molarfractions,weightfractions,andviscositiesofBis-MEPP/CHMA,Bis-
MEPP/t-BCHMA,andBis-MEPP/PEMAresins 55
Table3.3: PredictedtheoreticalandmeasuredshrinkagevaluesforBis-MEPP-based
copolymersystems 64
Table3.4: PhysicalpropertiesofBis-MEPP/PEMAsystems 65
Table3.5: PhysicalpropertiesofBis-MEPP/CHMAsystems 66
Table3.6: PhysicalpropertiesofBis-MEPP/t-BCHMAsystems 67
Table3.7: PhysicalpropertiesofBis-MEPP/EGDMA-typeresins 67
Table3.8: DegreeofconversionvaluesbasedonpercentvinylbondsremaininginBis-
MEPP/PEMA,Bis-MEPP/CHMA,andBis-MEPP/t-BCHMAsystems 69
Table3.9: DegreeofconversionvaluesbasedonpercentvinylbondsremaininginBis-
MEPP/EDGMA-typesystems,andtheBis-MEPP/PEMA,Bis-MEPP/CHMA,
andBis-MEPP/t-BCHMAsystemsformulatedtoapproximately35weight
percentdiluent 69
vn
Table3.10: Pair-wisecomparisonofthemodulusvaluesofdifferentpolymersystemsby
mol.%formulationinthewetstateusingStudent'st-test 73
Table3.11: Student'st-testscomparingtensilestrengthsofthevariousBis-MEPP/t-
BCHMAformulationsinthewetanddrystateandthesameformulationinits
wetanddrystate 79
Table3.12: Student'st-testscomparingwetfracturetoughnessvaluesofthevarious
formulationsinthewetstate 82
Table3.13: Statisticsontan8plotsandglasstransitionactivationsenergiesforpolymers
inthedrystateat1Hertz 88
Table3.14: WLFparametersusedtoobtainthemastercurvefitsfortheBis-
MEPP/PEMAandBis-MEPP/CHMAsystemsformulatedtoaglasstransition
temperatureof135°C 109
Table4.1: FeedbackparametersforTappingMode™AtomicForceMicroscopy 127
Table4.2: ParametersusedtocollectstandardxenonspectraofBis-MEPP(XDT)
samples 128
Table4.3: Hahnechosequenceparametersusedforwaterself-diffusioncoefficient
measurements 129
Table4.4: Parametersusedinpulsesequencetomeasuretheself-diffusioncoefficientof
xenoninBis-MEPP(XDT) 131
Table4.5: XenonNMRspectrumparametersforBis-MEPP(XDT)atvariousstagesof
cure 148
Table4.6: Degreeofconversionvalues,diffusioncoefficients,anddomainsizesofBis-
MEPP(XDT)atvariousstagesofcure 155
Table5.1: 2-phenylethylmethacrylate/nadicmethylanhydride/maleicanhydride
monomercompositionsinmol.% 162
Table5.2: FTIRandDSCresultsfrom2-phenylethylmethacrylate/nadicmethyl
anhydridebasedmodelcompounds 167
Table5.3: MolarmassaveragesfromGPCfor2-phenylethylmethacrylate-nadicmethyl
anhydridecopolymers 167
Table5.4: FTIRdataandDSCfrom2-phenylethylmethacrylate/nadicmethyl
anhydride/maleicanhydridebasedmodelcompounds 171
Table5.5: MolarmassaveragesfromGPCfor2-phenylethylmethacrylate-nadicmethyl
anhydride-maleicanhydridecopolymers 171

LISTOFFIGURES
Figure Page
Figure2.1: Thestructureof2,2-bis(4-(2-hydroxy-3-methacryloyloxyprop-l-
oxy)phenol)propane(Bis-GMA) 15
Figure2.2: Dimethacrylatessynthesizedfromvariousdiphenols 15
Figure2.3: Bis-GMAanalogsreferredtoinTable2.2 33
Figure2.4: EthoxylatedBis-GMAmolecules 34
Figure2.5: 2,2'-bis-(4-methacryloylpropoxyphenyl)propane(Bis-MPPP) 34
Figure3.1: Thestructureof2-phenyloxyethylmethacrylate(PEMA) 50
Figure3.2: Thestructureofcyclohexylmethacrylate(CHMA) 50
Figure3.3: Thestructureoft-butylcyclohexylmethacrylate(t-BCHMA) 50
Figure3.4: Thebasicstructureofpoly(ethyleneglycoldimethacrylate)analogs 54
Figure3.5: Schematicofmoldusedforsamplemanufacture.Source:[99] 57
Figure3.6: ViscositymeasurementsonBis-MEPP/PEMA,Bis-MEPP/t-BCHMA,and
Bis-MEPP/CHMAresinsat25°C 62
Figure3.7: ViscositymeasurementsofvariousdiluentsintheBis-MEPP-basedresin
systemsdilutedatapproximately35weightpercent 63
Figure3.8: FlexuremodulusvaluesofwetanddryBis-MEPP/CHMA,Bis-
MEPP/PEMA,andBis-MEPP/t-BCHMApolymersat37°C. Thelegend
representsthemonomersusedtodiluenttheBis-MEPPmonomer 71
Figure3.9: TensilestrengthvaluesofwetanddryBis-MEPP/PEMA,Bis-
MEPP/CHMA,andBis-MEPP/t-BCHMApolymersat37°C 84
Figure3.10: FracturetoughnessvaluesofwetanddryBis-MEPP/PEMA,Bis-
MEPP/CHMA,andBis-MEPP/t-BCHMApolymersat37°C 85