MISCIBILITY OF 3 DIFFERENT POLY(ARYL ETHER KETONES) WITH A HIGH-MELTING THERMOPLASTIC POLYIMIDE

Three poly(aryl ether ketone)s (PAEKs) were melt blended at 415-degree s-C with a new thermoplastic polyimide (N-TPI) composed of (4,4'bis(3- aminophenoxy) biphenyl) and pyromellitic dianhydride. The PAEKs studie d were poly(aryl ether ether ketone)(PEEK),poly(aryl ether ketone keto ne)(PEKK)and poly(aryl ether ketone) (PEK). Although chemically simila r, these three show distinctly different behaviour when blended. We ha ve concentrated on amorphous blends in this work so the difference in the crystallization rates of the PAEKs is not a factor in our determin ation of miscibility. It was found that PEEK was immiscible with N-TPI at all proportions. PEKK is the slowest crystallizing polymer and is miscible at most proportions, as evidenced by single glass transitions . PEK is miscible at N-TPI contents of less than approximately 50% and partially phase separated in the N-TPI rich blends. It is apparent th at the higher percentage of ketone linkages in the PAEKs correlates wi th the higher degree of miscibility. Charge transfer complexation coul d also be a factor but this has yet to be explored.