Conductive IPN based on polypyrrole and silicon crosslinked styrene-isoprene-styrene triblock copolymer

The conducting interpenetrating polymer network (IPN) is prepared by sequen tial crosslinking of tetrethyl orthosilicate (TEOS) with acrylic acid graft ed styrene-isoprene-styrene triblock copolymer (SIS) and polypyrrole doped with dodecylbenzenesulfonic acid (DBSA). The resulting IPN not only has goo d conductivity, but also exhibits far superior thermal stability. Various f actors affecting the properties of conductive IPNs are investigated. The am ounts of water and TEOS used have a profound effect on the conductivity. Si gnificantly, under appropriate experimental conditions, a conductive IPN wi th conductivity as high as that of pure PPyDBSA has been prepared. Heating the conductive IPNs to 140 degrees C has generally caused the conductivity to decrease. However, samples with conductivity relatively unaffected by th e heat treatment can be prepared with proper selections of H2O/TEOS ratio. The effect of heating on the conductivity is discussed. All the IPNs have e xcellent thermal stability as clearly shown by the results of thermal gravi tational analysis (TGA). The morphologies of the IPN films are investigated using a scanning electron microscope (SEM). (C) 1999 Elsevier Science Ltd. All rights reserved.