EffectsofPhotopolymerizablePrepolymerArchitectureonThermomechanicalProperties

ByJonScholteandAllanGuymonChemicalandBiochemicalEngineering

UniversityofIowa

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•  LineargradientshavebeenshowntoinfluencetheresoluBonandsizeofpolymerblendmorphology.

Guoetal.J.Poly.Sci.B.2015,53,860-868 2

•  LineargradientshavebeenshowntoinfluencetheresoluBonandsizeofpolymerblendmorphology.

Guoetal.J.Poly.Sci.B.2015,53,860-868 3

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Initiator Mediating Radical

SG-1

• •

I

Heat >50 oC

kc

Alkoxyamines

RAFT

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•  NitroxideMediatedPolymerizaBonrequires2subsequentfeedstosynthesizeanendfuncBonalizedprepolymer

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•  EndfuncBonalizedspeciescanbesynthesizedwithasinglefeedandgrowsfromtheinsideout

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•  BothNitroxideandRAFTmethodsallowforthesynthesisofrandomlyreacBveprepolymersfromasimpleonepotmethod

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Polymer Mn PDI Func4onality

N-End 11,000 1.4 8

N-Random 15,000 1.4 8

R-End 12,000 1.2 8

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0.5%wtDMPA10mW/cm26min

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EndfuncBonalformulaBonsshowlargeglasstransiBonforbutylacrylatebackboneandsecondforhddadomain

0.5%wtDMPA10mW/cm26min

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ConBnuousharddomainimprovesmodulusofendfunc4onalizedformulaBons

0.5%wtDMPA10mW/cm26min

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ConBnuousharddomainsinendfunc4onalmaterialsincreasesresistancetosuddenstress

0.5%wtDMPA10mW/cm26min

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1MPa

•  RearrangementaroundTrithiocarbonatebondwillallowforbothrelaxaBonandagreaterdistribuBonofso^segmentsthroughoutthenetwork

•  Ifrearrangementsareoccurring,theywouldcompetewithpropagaBonandthusalterreacBonkineBcs

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RAFTrearrangementretardsthepolymerizaBonathighprepolymerconcentaBons

0.5%wtDMPA10mW/cm215min

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NetworkrearrangementpreventscompletecureinRAFTformulaBons

0.5%wtDMPA10mW/cm215min

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RearrangementaroundRAFTgroupdiminishesphaseseparaBonandleadstogradualdecreasesinstoragemoduli

0.5%wtDMPA10mW/cm215min

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RAFTrearrangementdiminishesprimarybutylacrylateglasstransiBon

0.5%wtDMPA10mW/cm215min

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0.5%wtDMPA10mW/cm215min

•  RAFTrelievesstressandcreatessmallerso^domain

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Greatercon4nuityofharddomainsfurtherincreasesresistancetosuddenstress

0.5%wtDMPA10mW/cm215min

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1MPa

0.5%wtDMPA10mW/cm26min

Transferinrandomsystemsproducesextremelyrobustfilmsallowingforfurthertuningofthesystems.

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•  NitroxideandRAFTprocessescanbeusedtomakefuncBonalPrepolymers.

•  Architectureofprepolymermoleculesdirectlyeffectsmorphology

•  RAFTprocessesallowssmallerso^domainsandnetworkrelaxaBonproducingtoughermorerobustfilms

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•  GuymonGroup

•  TheUnversityofIowa•  IUCRC

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•  NitroxideandRAFTprocessescanbeusedtomakefuncBonalPrepolymers.

•  Architectureofprepolymermoleculesdirectlyeffectsmorphology

•  RAFTprocessesallowssmallerso^domainsandnetworkrelaxaBonproducingtoughermorerobustfilms

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