通过对多壁碳纳米管(MWNTS)／高密度聚乙烯(High density polyethylene,HDPE)复合材料的电阻- 温度特性进行了研究。发现MWNTs填充质量分数为1％-2％时,复合体系呈现渗流行为,表现出优异的导电性。同时体系存在特殊的V形温度系数特性(V-...通过对多壁碳纳米管(MWNTS)／高密度聚乙烯(High density polyethylene,HDPE)复合材料的电阻- 温度特性进行了研究。发现MWNTs填充质量分数为1％-2％时,复合体系呈现渗流行为,表现出优异的导电性。同时体系存在特殊的V形温度系数特性(V-PTC特性),即当MWNTs质量分数超过渗流阈值后,体系的电阻率随温度的升高先下降,出现负温度系数特性(NTC转变),然后才出现通常的正温度系数特性(PTC 转变),且具有很好的循环稳定性。V-PTC这种特性源于基体体积膨胀、MWNTs缠结链松弛以及基体的“退火”效应的协同作用。马来酸酐接枝苯乙烯-(乙烯-丁烯)-苯乙烯共聚物(MA-g-SEBS)的加入,可改善MWNTs 和HDPE之间的相互作用,并可基本上消除V-PTC特性,改善导电性。展开更多
Conductive properties of multiwalled carbon nanotubes(MWNTs) filled high-density polyethylene(HDPE) composites prepared by melt blending were studied. The results showed that as the MWNTs concents reach to 3%(mass fra...Conductive properties of multiwalled carbon nanotubes(MWNTs) filled high-density polyethylene(HDPE) composites prepared by melt blending were studied. The results showed that as the MWNTs concents reach to 3%(mass fraction), the electrical conductivity of the composites changes from insulator to semiconductor, possessing resistivtiy of 10 10 Ω·cm. While as the MWNTs concents reach to 5%, the composites become a good conductor. The resistivity-temperature characteristic of the composites exhibits that with the increasing of the temperature, the resistivity of the composites first decreases, while increases abruptly when the temperature approaches melting point(t_m) of the matrix, indicating an existence of the negative temperature coefficient(NTC)-positive temperature coefficient(PTC) effect. It should be noted that this phenomenon can not be found in polymer-based composites filled with other conductive particles, such as carbon black, graphite, carbon fiber.展开更多
文摘Conductive properties of multiwalled carbon nanotubes(MWNTs) filled high-density polyethylene(HDPE) composites prepared by melt blending were studied. The results showed that as the MWNTs concents reach to 3%(mass fraction), the electrical conductivity of the composites changes from insulator to semiconductor, possessing resistivtiy of 10 10 Ω·cm. While as the MWNTs concents reach to 5%, the composites become a good conductor. The resistivity-temperature characteristic of the composites exhibits that with the increasing of the temperature, the resistivity of the composites first decreases, while increases abruptly when the temperature approaches melting point(t_m) of the matrix, indicating an existence of the negative temperature coefficient(NTC)-positive temperature coefficient(PTC) effect. It should be noted that this phenomenon can not be found in polymer-based composites filled with other conductive particles, such as carbon black, graphite, carbon fiber.
