A series of novel polyimides containing naphthalene pendant moieties were prepared from various diamines (including bis(4-amino-3,5-dimethylphenyl)naphthylmethane 1, bis(4-aminophenoxy-3,5-dimethylphenyl)naphtyhlmethane 4, and bis(4-aminophenoxy-3,5-dimethylphenyl)methane 5) with various aromatic tetracarboxylic dianhydrides via both two-step and one-step methods. All polyimides, except 8(5a-d), were readily soluble in common organic solvent, such as chloroform. Differential scanning calorimetry (DSC) revealed that the naphthalene bearing diamine monomers had a low entropy, and formed amorphous polyimides. They retained high moduli even at high temperatures by DMA, and had measured coefficients of thermal expansion (CTEs) in the range of 46.86-67.14ppm by TMA. The glass transition temperature (Tg) Of all polyimides were found to be 268-294 degrees C, 298-326 degrees C and 270-315 degrees C, respectively by DSC, DMA, and TMA. Thermogravimetric analyses indicated that the polymers were fairly stable up to 489-571 degrees C (10 wt% loss in N-2). They had a tensile strength in the range of 56-97 MPa, and elongations to break of around 3%. These polyimide films have dielectric constants ranging from 2.71 to 3.28 with moisture absorptions of less than 0.98%. (C) 2000 Elsevier Science Ltd. All rights reserved.