POLY(ARYL ETHER KETONE) BLOCK AND CHAIN-EXTENDED COPOLYMERS .1. PREPARATION AND CHARACTERIZATION OF A NEW CLASS OF FUNCTIONAL POLY(ARYL ETHER KETONE) OLIGOMERS

A series of poly(aryl ether ketone) (PAEK) oligomers with controlled molecular weights and end groups has been prepared via the Friedel-Crafts reaction of terephthaloyl chloride with diphenyl ether in the presence of either p-fluorobenzoyl chloride or fluorobenzene as the chain-terminating agents. The p-fluorobenzoyl chloride route is preferred, and the reaction is carried out in 1,2-dichloroethane, at 20-30 wt % solids, in the presence of a 30-40 mol % excess of aluminum chloride. A troublesome side reaction involving alkylation of the benzene rings is minimized under these conditions and is further minimized by the addition of a complexing agent. The oligomers were characterized by fluorine content, C-13 NMR, laser desorption-mass spectrometry, and GPC, which proved to be a powerful tool for the determination of purity. The fluorine contents agreed well with calculated values indicating a high degree of difunctionality.