聚合物基PTC材料稳定性的研究

提高导电复合材料的PTC(Positive Temperature Coefficient)强度和稳定室温电阻的重现性,是研究和使用聚合物基PTC材料所追求的目标.PTC材料经过在开关温度及其以上的较宽温度范围内重复热循环后,室温电阻升高,PTC强度降低.研究了辐射交联和在不同气氛中长时间热老化对聚合物基PTC复合材料的室温电阻、PTC强度、结晶度和开关温度等性能的影响.结果表明:辐射交联和氮气氛保护均有利于提高PTC材料的电性能稳定性,室温电阻和PTC强度的变化率相对较小.

Study on Stability of Polymer-Based PTC Composites

The objective in studying and using polymer based PTC (Positive Temperature Coefficient) materials is to increase PTC intensity of conductive composites and stabilize the reproducibility of the room temperature resistivity. On repeated heating cycling through the switch temperature or above it, the room temperature resistivity rises and the PTC intensity decreases. The effects of radiation cross linking and continuous thermal aging in various atmospheres for a long time on the properties of the polymer based PTC materials, such as the room temperature resistivity, PTC intensity, crystallinity and switch temperature, were studied. The results indicated that radiation cross linking and nitrogen atmosphere were both favor of improving the electricity stability of PTC materials, the variety ratios of the room temperature resistivity and PTC intensity were relatively small.