Synthesis and characterization of poly(ether ketone ketone) (PEKK)/sodium sulfonated poly(arylene ether ketone) (S-PAEK) block copolymers

A series of well-defined poly(ether ketone ketone) (PEKK)/sodium sulfonated poly(aryl ether ketone) (S-PAEK) block copolymers of high molecular weights was prepared by direct nucleophilic polymerization of hydroquinone with sodium 5,5 ' -carbonylbis (2-fluorobenzene sulfonate) (1) and PEKK oligomer (2). Varying the ratio of 1 to 2 used in polymerization can be used to control the degree of polymer sulfonation, which correspondingly affects the polymer solubility in solvents. Increasing content of 1 in the copolymers, slightly decreases their thermal stability which is nevertheless thermally stable up to 400 degreesC. Two T-g values, or one broad T-g, were observed in the DSC measurements of the block copolymers, indicating the existence of phase separation, which was further proved by phase-separated morphologies as shown in atomic force microscopy images. (C) 2001 Society of Chemical Industry.