A series of polyimide (PI) thin films were synthesized based on bis[3,5-dimethyl-4-(4-aminophenoxy)phenyllmethane and conventional aromatic dianhydrides. The structures and properties of the thin films were measured with Fourier transform infrared, NMR, thermogravimetric analysis, dynamic mechanical analysis, and impedance analysis. The PI films exhibited glass-transition temperatures in the range of 211-300 degrees C and possessed initial thermal decomposition temperature reaching up to 457-482 degrees C in air and 461-473 degrees C in nitrogen. Some PI films had high solubility in organic solvents such as 1-methyl-2-pyrrolidinone, NN-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, m-cresol, tetrahydrofuran, and CHCl3. The mechanical properties of these films were also examined. The dielectric constants of the films were in the range of 2.8-3.3 at 25 degrees C. (c) 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1265-1270, 2007.