Synthesis, Characterization and Thermal Stability of Novel Carborane- Containing Epoxy Novolacs

(整期优先)网络出版时间:2016-09-19
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Carboranebisphenolnovolacs(3and4)weresynthesizedinthepresenceofacidcatalystfromcarboranebisphenols(5and6)andformaldehyde.Furtherepoxidizationofcarboranebisphenolnovolacswithepichlorohydringavecarboranebisphenolepoxynovolacs(1and2).Themolecularweightandepoxyvalueofobtainedresinsweredeterminedusingthemolecularweightoftheirprecursors.Theepoxyvaluesof1and2were0.48and0.52respectively,higherthanthemaximumtheoreticalepoxyvalue(0.45)ofdifunctionalcarboranebisphenolepoxyresins.FTIRandNMRwereutilizedtocharacterize1and2.ThecuringbehaviorswerealsostudiedbyDSCandtheoptimizedcuringconditionswereobtained.TGAanalysisindicatedthatcarboranemoietycouldshielditsadjacentorganicstructuresagainstinitialdecomposition.Ontheotherhand,B―Honcarboranecagecouldreactwithoxygentoformathree-dimensionalnetworklinkedbyB―O―BandB―Cbonds,whichfurtherblockedthemovementofformedradicalsandthusthedegradationprocesswasinhibited.