Conducting polymer blends of poly(3-octylthiophene) and poly(vinyl chloride) and the influence of a plasticizer on the compatibility

Meltmixed conducting polymer blends of poly(3-octylthiophene), POT, and poly(vinyl chloride), PVC, have been examined according to their conductivity, miscibility behaviour and their morphology. After doping with FeCl3, these blends show a relatively high conductivity (∼3 S/cm for 23% POT). Phase structure and miscibility have been studied with electron microscopy and dynamic mechanical measurements, respectively. These studies reveal that POT and PVC form an immiscible blend which can be co-continuous even with a relatively low content of POT. By adding the plasticizer di-iso-octyl phthalate, DOP, the conductivity can be increased even if the content of POT is decreased.