Abstract: Electrical conductivity property and responsiveness to organic solvent vapors of poly( methyl methacrylate) /poly( ethylene glycol)/carbon black(PMMA/PEG(/CB) composites synthesized through in-situ polymerization were investigated. When the mass ratio of MMA/PEG was 8/1, it took only 20~30 min for the monomers to reach a conversion of 94 %. Afte r 8.5 wt% of carbon black was intro. duced, the composite gave a resistivity of 1.3 Ω cm. It was fou Ind that the electric resistances of the composites drastically increased by 10⁴ times when the materials w were exposed to good solvent vapors of PMMAsuch as acetone, chloroform, and ethyl acetate, but only 140 times to poor solvent methanol. These results suggested that the composites could be regarded as a promising gas sensor.

Key words: poly ( methyl methacrylate );poly ( ethylene glycol );carbon black, conductive composite;electrical conductivity, organic vapor, electrical resistance response