POLY(ARYL ETHER KETONE) (PAEK) BLOCK AND CHAIN-EXTENDED COPOLYMERS .2. PREPARATION AND CHARACTERIZATION OF CHAIN-EXTENDED PAEK COPOLYMERS AND POLY(ETHER KETONE KETONE) POLY(ETHER ETHER KETONE) BLOCK COPOLYMERS

A series of chain-extended poly(aryl ether ketones) (PAEKs) and poly(e ther ketone ketone)/poly(ether ether ketone) (PEKK/PEEK) block copolym ers have been prepared via the nucleophilic polycondensation and evalu ated. The former were prepared by reacting a bisphenol, such as hydroq uinone, with a series of difunctional PAEK oligomers, while the latter were prepared by reacting those same oligomers with a bisphenol, such as hydroquinone, and an activated dihalo compound, such as 4,4'-diflu orobenzophenone. The chain-extended copolymers show good mechanical an d thermal properties which can be varied by varying the particular bis phenol used and/or the oligomer molecular weight. The PEKK/PEEK block copolymers also have overall attractive properties; an in-depth evalua tion of one particular polymer showed properties comparable to those o f commercial poly(aryl ether ketones).