Polypyrrole nanoparticles coated amorphous short silica fibers: Synthesis and characterization

摘要

Polypyrrole-coated amorphous silica short fibers (PPy-ASF) were obtained through in situ oxidative polymerization of pyrrole (Py) on the ASF surface by using ferric chloride (FeCl _3) as oxidant. These conducting fibers were constituted of PPy particles packed close together to form a continuous conductive layer on the ASF surface which was responsible for electrical conductivity of 0.32 S.cm ~(-1), similar to that found for pure PPy. The PPy-ASF were blended with polystyrene-block-poly(ethylene-ran-butylene)-block- polystyrene copolymer (SEBS) through solution casting at room temperature to form conductive rubbery (SEBS/PPy-ASF) composites. The electrical conductivity and percolation threshold of SEBS/PPy-ASF films were evaluated and also compared with PPy filled SEBS blends (SEBS/PPy) prepared under the same processing conditions. SEBS/PPy-ASF displayed lower percolation threshold and higher electrical conductivity values than those found for SEBS/PPy blends at the same conductive filler concentration. The high PPy-ASF aspect ratio (length to diameter ratio, L:D) and their good electrical conductivity allow production of conductive polymer composites at very low percolation threshold. The results obtained in this study reveal that PPy-ASF materials are promising candidates to be used as conductive filler for developing conducting polymer composites.