Summary: Flexible heaters were prepared by extruding platinum‐catalyzed silicone rubber compound with electroconductive carbon black (CB) and SnO2/Sb coated titanium dioxide (TiO2). Two types of acicular‐shaped TiO2 with average particle sizes of 1.7 and 5.2 µm, and two types of spherical‐shaped TiO2 with average particle sizes of 0.3 and 2.5 µm were selected. Thermoelectric switching phenomena were investigated for the silicone rubber/CB/TiO2 system. Positive temperature coefficient (PTC) was significant when the acicular filler was added rather than spherical ones. Resistivity change and thermal reproducibility of the extruded heaters were also investigated by applying periodically AC voltage of 220 V. The heaters containing acicular‐shaped TiO2 exhibited excellent electrical reproducibility.
Scanning electron micrograph of the fractured surface of the extruded composites.
