New monomers, 4,4'-bis(4-phenoxybenzoyl)diphenyl (BPOBDP) and N, N'-bis(4-phenoxybenzoyl)-4,4'-diaminodiphenyl ether (BPBDAE), were conveniently synthesized via simple synthetic procedures from readily available materials. Novel copolymers of poly(ether ketone diphenyl ketone ether ketone ketone) (PEKDKEKK) and poly(ether amide ether amide ether ketone ketone) (PEAEAEKK) were synthesized by electrophilic Friedel-Crafts solution copolycondensation of isophthaloyl chloride (IPC) with a mixture of BPOBDP and BPBDAE, over a wide range of BPOBDP/BPBDAE molar ratios, in the presence of anhydrous AlCl3 and N-methylpyrrolidone (NMP) in 1,2-dichloroethane (DCE). The copolymers obtained were characterized by different physicochemical techniques. The copolymers with 10-40 mol% BPBDAE are semicrystalline and had remarkably increased T(g)s over commercially available PEEK and PEKK due to the incorporation of amide and diphenyl linkages in the main chains. The copolymers IV and V with 30-40 mol% BPBDAE had not only high T(g)s of 185-188 degrees C, but also moderate T(m)s of 326-330 degrees C, having good potential for the melt processing. The copolymers IV and V had tensile strengths of 101.7-102.3 MPa, Young's moduli of 2.19-2.42 GPa, and elongations at break of 13.2-16.6% and exhibited high thermal stability and excellent resistance to organic solvents. (C) 2013 Society of Plastics Engineers