Electrically Conductive Sealing Silicone Compositions Filled with Carbon Materials

Electrically conductive sealants and coatings have been of great interest in recent years due to advances in electronics and technology. There are not many studies that use siloxanes as matrices. This work aimed to obtain an inexpensive electrically conductive composite using a silicone matrix and carbon fillers: carbon black, graphite, and coal. Introducing a carbon filler led to a significant change in the electrical conductivity of the silicone composite. With an increase in the carbon filler in the composite material from ۵ to ۳۰ wt.% there was a natural increase in its electrical conductivity from ۱۰-۹ –۱۰–۴ up to ۸.۳×۱۰-۶ – ۱.۱۱×۱۰۲ (Ohm×m) -۱. This trend is observed for all types of carbon filler. The lower conductivity of graphite and activated carbon is due to the polycrystalline structure and the content of amorphous carbon. The SEM method has established the distribution of particles in the composite matrix with an increase in the filler content, which contributes to a denser packing of aggregates and closer contact between them, due to which conditions are created for the formation of electrically conductive circuits. In this work, the best filler for the electrically conductive sealant was carbon black, at a content of ۳۰% wt. demonstrating an electrical conductivity of ۱.۱۱×۱۰۲ (Ohm×m)–۱. However, an increase in the content of carbon black in the matrix hurt the physical and mechanical properties, the nominal tensile strength decreased by ۴۲%, and the elongation at the break by ۳۷%. The resulting composite can be used as an electrically conductive sealing material, but there is a need to improve the physical and mechanical characteristics.

کلیدواژه ها:

Sealing materials ، carbon materials ، Carbon fillers ، Siloxanes ، Resistivity ، carbon black ، Electrical conductivity ، Nanocomposites