Fine powders of ketone-containing aromatic polymers and process of manufacture

Fine particles of semi-crystalline ketone-containing aromatic polymers (PEEK, PEKK, etc.) are produced by controlling the rate and conditions of hydrolysis of an amorphous polyarylketimine intermediate. The choice of acid and its concentrations affects the rate of ketimine hydrolysis and subsequent particle formation. In addition, zero or reduced amounts of agitation during hydrolysis has been found to promote the formation of smaller (submicron) sized particles which are spherical in shape, while greater amounts of agitation or shear stress applied during hydrolysis results in nonspherical, larger particles. Carbon fiber reinforced composites were made from aqueous suspensions of these particles that were dispersed or stabilized by a water soluble polymer.