A series of pyridine-containing poly(imidesiloxane) (PIS) copolymers with different amounts of PDMS with various segmental lengths were synthesized from 2,6-diaminopyridine (DAP), alpha,omega'-aminopropylpoly(dimethylsiloxane) (PDMS), 1,3-bis(4-aminophenoxy)benzene (APB), and 4,4'-oxydiphthalic dianhydride (ODPA). A modified synthetic approach was applied instead of approaches commonly reported in the literature, to ensure the incorporation of DAP and PDMS. The effects of the content and the segmental length of PDMS on the thermal glass transition temperature (T-g), dielectric constant, and surface electrical resistivity of the copolymer are investigated. The copolymers were attached to copper foil by hot-pressing, and changes in wettability caused the peel strength of the laminates to increase with the PDMS content, but to decrease as the DAP content increased. Furthermore, X-ray photoelectron spectroscopy was employed to determine the loci of failures (LOF) of the laminates and to monitor the movement of LOF, which varies with the PDMS content. For those laminates with good peel strengths, the LOF occur in the interior of PIS layer, indicating that the adhesion is cohesive rather than adhesive. (c) 2007 Wiley Periodicals, Inc.