The Synthesis of Conductive Nano-composites by a Selective in situ Polymerization of Pyrrole Within the Lamellar Microdomains of a Block Copolymer
Electrically conductive nanocomposites were prepared by a selective in situ polymerization of pyrrole within the lamellae ionomeric microdomains of sulfonated poly(styrene-b-(ethylene-alt-propylene)), SEP, diblock copolymers. A conductivity of 10-3−10-1 S/cm was achieved parallel to the film surface for PPy concentrations from 5 to 11 wt % PPy. Although the microstructure of the block copolymer was not purposefully aligned, the conductivity was anisotropic, varying 1−2 orders of magnitude parallel and normal to the plane of the composite films. The in situ polymerization of pyrrole in the SPS microphase did not disrupt the texture of the block copolymer microstructure, though the interphase between the polystyrene and rubber lamellae became more diffuse. Incorporation of PPy also improved the modulus of the block copolymer above the Tg of the ionomer microdomains.