高密度聚乙烯/石墨导电复合物的PTC行为及其热循环稳定性
PTC Behavior and its Stability for High Density Polyethylene/Graphite Composites
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摘要: 研究了高密度乙烯/石墨导电复合物的PTC行为及其影响因素,揭示了内应力随温度升高而松驰对PTC效应的贡献。复合物的导电性能与PTC行为是电导网络的总体结构及其随温度的变化所决定的,与材料组分性质以及各组分之间的相互作用关系不大。当环境温度趋于基体熔点时,复合物热学性质的变化造成导电网络的大规模破坏,是PTC行为产生的根源。热处理等物理手段可改变导电网络的微观结构,但不影响PTC行为赖以产生的物理机制,也不能有效改善PTC行为的热循环稳定性。Abstract: The PTC behavior and its stability of high-density polyethylene/graphite (HDPE/GP) composites were studied. The results show that the internal stress is one of the factors which result in the PTC transition and influence the PTC behavior. The conduction a