Synthesis, characterization, crystallization of poly(ether ketone ketone)

The all para polyether ketone ketone (PEKK) which possesses good mechanical properties was synthesized by the high temperature condensation reaction between 1, 4-bis (4′ -hydroxybenzoyl) benzene and 1, 4-bis (4′ -fluorobenzoyl) benzene, the general properties of PEKK were characterized by DSC, IR, TGA, WAXD and Mechanical Properties Measurement. The results indicate that the melting temperature of PEKK is 50 °C higher than that of PEEK and still keep the high temperature resistant property of PEEK, the crystallization structure of PEKK still assigns to orthorhombic' system. When amorphous PEKK was annealed below 230 °C , the glass transition temperature increase with the increasing of the heat treatment temperature, while above 230 °C , the glass transition temperature keep a constant, the low melting peaks linearly increase when annealing temperature are increased, the high melting peaks keep a constant regardless of the heat treatment temperature. The crystal structure of the slow-cooling crystallization specimens have a distinction with that of heat treatment crystallization samples.