Communication: The role of hydrogen bonding in the formation of homogeneous blends of conducting (polypyrrole) and insulating (poly(bisphenol-A-carbonate)) polymers is examined. The blends exhibit improved mechanical properties over the brittle pure conducting polymers and it has been suggested that the hydrogen bonding arises from the interaction of carbonyl groups in the insulating polymer and NH groups in the polypyrrole. To test this hypothesis, N-methylpyrrole, which is incapable of hydrogen bonding, is used in the blends and the resulting materials studied.