Grafting polythiophene on polyethylene surfaces

Polythiophene (PT) was grafted on PE film using three reaction steps. First, PE films were brominated in the gas phase, yielding PE–Br; second, a substitution reaction of PE–Br with 2‐thiophene thiolate anion gave the thiophene‐functionalized PE; finally PT was grafted on the PE surface using chemical oxidative polymerization to give PE–PT. The polymerization was carried out in a suspension solution of anhydrous FeCl₃ in CHCl₃, yielding a reddish PE–PT film after dedoping with ethanol. ATR‐FTIR shows that the PT was grafted on PE in the 2,5‐position. SEM imaging revealed islands of PT on the PE film. AFM analysis found the thickness of islands to be in the range of 120–145 nm. The conductivity of these thin films was in the range of 10^?6 S cm^?1, a significant increase from the value of ～10^?14 S cm^?1 measured for PE film. © 2003 Society of Chemical Industry