A series of copolymers were prepared by the reaction of various bisphenols with a 50:50 molar ratio of two bisfluoro compounds, 4,4'-bis(1-fluoro-2-trifluoromethyl benzyl) benzene and 4,4'-difluorobenzophenone. The synthesized polymers were well characterized for their thermal, mechanical, and electrical performances. The copolymers showed a better set of properties than their analogous homopolymers derived from 4,4'-bis(1-fluoro-2-trifluoromethyl benzyl) benzene and bisphenols. The microstructures of the copolymers were analyzed by H-1-, C-13-, F-19-, distortionless enhancement by polarization transfer 90, two-dimensional H-1-H-1 homonuclear correlation spectroscopy, and C-13- H-1 correlation spectroscopy NMR techniques. (c) 2005 Wiley Periodicals, Inc.