Electrically conductive polymer composites: polymerization of acetylene in polyethylene

Abstract

Composites of low density polyethylene, LDPE, and polyacetylene, (CH) x , were prepared by polymerization of acetylene in LDPE films impregnated with a Ti(OBu) 4 Et 3 Al Ziegler-Natta catalyst. LDPE films were immersed in a toluene solution of this catalyst at 70°C to accomplish impregnation. Polymerization of acetylene in the LDPE films was carried out at 100°–110°C. The resulting composite films remain flexible and tough upon prolonged air exposure and those containing < ca. 5 wt.% (CH) x soften upon heating to 120°–160°C. The films can be rendered conductive upon exposure to a 2 wt%. solution of l 2 in pentane. Ultimate conductivities of ca. 10Ω −1cm −1 can be obtained. The conductivities of the doped composites decay more slowly as compared with l 2-doped (CH) x films. The synthetic approach, with some simple modifications, can be used in the construction of many electrically conductive, all-polymer composites having a combination of desirable physical, mechanical and electrical properties.