Several novel aromatic poly(ether ketone)s containing pendant methyl groups and sulfone linkages with inherent viscosities of 0.62-0.65 dL/g were prepared from 2-methyldiphenylether and 3-methyldiphenylether with 4,4'-bis(4-chloroformylphenoxy)diphenylsulfone and 4,4'-bis (3-chloroformylphenoxy)diphenylsulfone by electrophilic Friedel-Crafts acylation in the presence of N,N-dimethylformamide with anhydrous AlCl3 as a catalyst in 1,2-dichloroethane. These polymers, having weight-average molecular weights in the range of 57,000-71,000, were all amorphous and showed high glass-transition temperatures ranging from 160.5 to 167 degrees C, excellent thermal stability at temperatures over 450 degrees C in air or nitrogen, high char yields of 52-57% in nitrogen, and good solubility in CHCl3 and polar solvents such as N,N-dimethylformamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone at room temperature. All the polymers formed transparent, strong, and flexible films, with tensile strengths of 84.6-90.4 MPa, Young's moduli of 2.33-2.71 GPa, and elongations at break of 26.1-27.4%. (C) 2007 Wiley Periodicals, Inc.