PTC properties of PE/CB composites for energy saving heating elements

ABSTRACT

Polyethylene/carbon black(PE/CB) composites have been widely used in various application devices such as heating element, temperature sensor and current limiter due to its positive temperature coefficient (PTC) effect. It is well known that the PTC effect is generated owing to a great thermal expansion caused as the result of dissolution of the crystal. In this study, in order to develop the excellent energy saving heating elements, we manufactured PE/CB composites. We systematically investigated the PTC properties of PE/CB composites. The SEM results show that CB element homogeneously diffuses into PE. The resistivity jump characteristics (ρ_max/ρ_min) and temperature coefficient of resistivity(α) of Bi(NaBa)TiO₃ ceramics were better than those of PE/CB composites. However, PE/CB composite was suitable for energy saving heating element application because the PE/CB composites showed proper PTC properties.

KEYWORDS:

• Positive temperature coefficient (PTC)
• polyethylene/carbon black(PE/CB) composites
• resistivity jump