Synthesis and Properties of Copolymers of Poly(ether ketone ketone) and Poly(ether ether ketone ketone) Containing Naphthalene Moieties and Pendant Cyano Groups

A new monomer containing naphthalene, 2,6-bis(beta-naphthoxy)benzonitrile (BNOBN) was synthesized by reaction of beta-naphthol with 2,6-difluorobenzonitrile in N-methyl-2-pyrrolidone (NMP) in the presence of KOH and K(2)CO(3). Novel copolymers of poly(ether ketone ketone) and poly(ether ether ketone ketone) containing naphthalene moieties and pendant cyano groups were prepared by electrophilic Friedel-Crafts solution copolycondensation of terephthaloyl chloride (TPC) with varying mole proportions of diphenyl ether and 2,6-bis(beta-naphthoxy)benzonitrile (BNOBN) using 1,2-dichloroethane as solvent and NMP as Lewis base in the presence of anhydrous AlCl(3). The crystallinity and melting temperatures of the polymers were found to decrease as the concentration of BNOBN in the polymer increased, whereas the glass transition temperatures of the polymers increased as the concentration of BNOBN in the polymer increased. The copolymers with 20-25 mol% BNOBN had high T(g) values of 182-184 degrees C; moderate T(m) values of 324-335 degrees C; tensile strengths of 101.8-103.2 MPa, Young's moduli of 3.14-3.23 GPa, and elongations at break of 15-18%. The copolymers exhibited outstanding thermal stability and good resistance to organic solvents, acidity and alkali.