Hyperbranched poly(ether ether ketone)s: preparation and comparison of properties with the corresponding dendrimers

Abstract

Hyperbranched poly(ether ether ketone)s with hydroxyl terminal groups are prepared by a one-step polycondensation of 3,5-dihydroxy-4′-(4-fluorobenzoyl)diphenylether (AB2-type monomer) through an aromatic nucleophilic substitution reaction. With the help of model compounds, 1H-NMR studies reveal that the degree of branching of the poly(ether ether ketone)s is about 52%. The possibility of entanglement among the hyperbranched polymer molecules is suggested from comparison of their glass transition temperatures with the corresponding dendrimers and the optimized structure of the hyperbranched polymers. The terminal hydroxyl groups were readily functionalized, yielding hyperbranched polymers with a variety of different functional chain ends. The nature of the chain end is shown to dramatically affect the properties of the hyperbranched polymers. Hyperbranched poly(ether ether ketone)s with hydroxyl terminal groups were prepared by a one-step synthesis of an AB2-type monomer 3,5-dihydroxy-4′-(4-fluorobenzoyl)diphenylether through an aromatic nucleophilic substitution reaction. The degree of branching determined by 1H-NMR analysis was about 52%. The reduced viscosities of the hyperbranched polymers were higher than those of the corresponding dendrimers, the glass transition temperatures of the hyperbranched polymers were higher than those of the dendrimers and the existence of entanglement among the hyperbranched polymer molecules was suggested.