The effect of various material parameters on PTC phenomena was studied for the composite systems of PE and carbon black in the temperature range of 20℃ and 180℃. The PTC characteristics were affected more or less by material parameters such as carbon black content, polymer composition and its network formation by crosslinking reaction, and the interfacial condition between polymer and carbon black. It was observed that PTC phenomena can be obtained in the lowed temperature region by the addition of low molecular weight species such as PE wax, and carnauba wax, EVA. For the better reproducibility in the PTC phenomena the crosslinking reaction of polymers by electron beam irradiation was more effective than the surface treatment of carbon black by coupling agents such as silanes and titanates.

카본 블랙의 무게함량비, 고분자 물질의 가교, 고분자와 carbon black 사이의 계면처리 등과 같은 변수에 따라 변화하는 폴리에틸렌 (PE)/카본 블랙 복합재료의 PTC (positive temperature coefficient) 현상을 상온∼180℃ 온도범위에서 조사하였다. 낮은 용융온도를 갖는 저분자량 물질을 첨가하여 저온영역에서 PTC특성을 얻을 수 있었다. PTC재료의 가장 큰 난점인 재현성의 향상을 위하여 silane, titanate계 계면결합제와 전자선가속기를 사용하였는데 전자선가교, silane계, titanate계의 순서로 좋은 재현성을 나타내었다. 또한, PTC재료 내부의 온도분포를 측정한 결과 이론적으로 계산한 값과 잘 일치함을 볼 수 있었다.

Keywords: positive temperature coefficient; electron beam radiation; crosslinking treatment