An electrically conductive composite of polyurethane pre-polymers was prepared by anintramolecular hydrogen transfer reaction using a reactive hydroxyl-terminatedpolybutadiene (HTPB) liquid rubber oligopolymer as a reactant, toluene diisocyanate(TDI) as a curing agent and carbon black (CB) as a conductive filler. The influence of thecomponent ratios, types of carbon black particles, curing temperatures and chain-extendingagents such as glycerine and triethanolamine on the responsiveness and reversibility ofHTPB/TDI/CB composite films was investigated. The structural characterization of thecuring materials was conducted on a FT-IR spectrometer. The experimental resultsindicated that a higher response behavior of HTPB/TDI/CB composite films occurred innon-polar solvent vapors than with polar solvent vapors. The response intensity of thecomposite films enhanced with increased TDI content and the introduction ofchain-extending agents. The responsivity of the films to benzene vapor reached106 times the original value, but the responsive time and recovery time were prolonged athigher curing temperatures. The response mechanism for the films was elucidated based onthe relationship between soft chain segments and hard chain segments.