Inordertoimprovethemechanicalpropertiesofpolypyrrole,compositesweremadebyelectropolymerizingpolypyrroleinapolyurethanematrix.Polypyrrole/polyurethane(PPY/PU)compositefilmscontainingCLO4-,BF4-orCH3-C6H4-SO3-counterionsweremadeinavarietyofsolventsystemsandcharacterizedbySEM,electronicconductivity,FTIR,andmechanicalproperties.Compositefilmsshowingmuchgreaterfiexibilitythanpurepolypyrrolewereobtained,buttheirelectronicconductivitiesweresubstantiallylower.Measuredeonductivitiesrangedfrom0.001to8S/cm,tensilestrengthsfrom44to592psi,andelongationtofailurefrom3to70%.