NOVEL HYPERBRANCHED POLY(PHENYLENE OXIDE)S WITH PHENOLIC TERMINAL GROUPS: EFFECTS OF REACTION TIME AND CORE MOLECULES ON THE MOLECULAR WEIGHT AND POLYDISPERSITY

Anovelhyperbranchedpoly(phenyleneoxide)(HPPO)withphenolicterminalgroupswaspreparedfrom4-bromo-4′,4″-dihydroxytriphenylmethaneasAB2monomerindimethylsulfoxide(DMSO)viaamodifiedUllmannreaction.Themolecularweightandpolydispersity(PD)oftheresultingpolymersincreasedwithincreasingreactiontime.Inthepresenceofcoremolecules(bisphenolAand1,3,5-trihydroxybenzene),whichhavethesimilarmolecularbackbonestothereactivemonomer,themolecularweightcouldbecontrolledbyvaryingthecore-to-monomerratio.Incorporationofaverysmallamountofcoremoleculescouldleadtoahighermolecularweightascomparedwiththatwithouttheadditionofcoremolecules.However,whenthecorecontentreachedcertainextent,themolecularweightwoulddecreasewiththefurtherincreaseinthecorecontent.AnewsimilarbehaviorofcontroloverthePDwasalsoobtained.Theresultingpolymerswerecharacterizedby1H-NMR,13C-NMR,FT-IR,andGPC.