Research On Resistance-temperature Characteristics Of Rubber Filled By Carbon Black

Conductive composites with a certain resistance-temperature characteristicscould be prepared with a certain amount of conductive particles (metal particles,conductive carbon black, etc.) filled in the silicone rubber. This paper describesthe research status of conductive silicone rubber. The PTC resistance temperaturecharacteristic of the conductive composite materials had been deeply researched, itis of great significance for the practical application of conductive polymers.Research on resistance-temperature characteristics of rubber filled by carbonblack is divided into the following three aspects:First, micro-structure of different carbon black volume fractiontemperature-sensitive conductive rubber was investigated by scanning electronmicroscopy (SEM). Based on the General Effective Media Theory and themechanism of the positive temperature effect of the conductive silicon rubber,the resistance-temperature calculation model of the carbon black filled siliconerubber be derived.Second, General Effective Media Theory has been used to study the sensitivitycoefficient of the temperature-sensitive conductive rubber. Experimentally studiedthe range、stability and linearity of the temperature-sensitive conductive siliconrubber with different carbon black content, the results show that: The volumefraction of carbon black is a major factor in the resistance temperaturecharacteristic of the carbon black/silicone rubber. With the effectof the temperature field, the impact of temperature on the composite is mainlyreflected in the composite filling volume. It concluded that reason of positivetemperature coefficient of resistance for temperature-sensitive conductive rubberwas the changes of resistivity.When the carbon black volume fraction is close tothe percolation threshold, the carbon black/silicone rubber with high temperaturecoefficient of resistance and range.Third, Combined with the factors of the impact of resistance temperaturecharacteristics of carbon black/silicone rubber, Carbon nanotubes and carbonblack filled silicone rubber by a certain percentage, the stability of temperaturesensitive of carbon black/silicone rubber be improved. The results show that, the carbon black and carbon nanotubes filled in silicone rubber can improvethe stability of its resistance. The temperature coefficient of resistance and rangecould be enhanced by the foam rubber.