Electrical conductivity and dynamic mechanical properties of silicon rubber-based conducting composites: effect of cyclic deformation, pressure and temperature

Abstract

The effects of cyclic deformations such as bending and compressive flexing, temperature and pressure on electrical and dynamic mechanical properties of conductive polydimethylsiloxane (PDMS) composites have been investigated. Conductive elastomeric composites were prepared by incorporating various carbon blacks in insulating PDMS matrix. Electrical conductivity was measured against varying concentration of different carbon blacks to assess the percolation threshold of the composites. AC and DC conductivity was found to increase with an increase in some bending flex cycles. However, with compressive flexing, DC conductivity initially dropped but later started increasing with an increase in flex cycles. The variations in electrical conductivity and dynamic mechanical modulus due to bend flexing are found to be similar, i.e. both characteristics show an increase in magnitude with an increase in some flex cycles. DC resistivity was found to increase with heating–cooling cycles, and this change in resistivity did not follow the same path leading to electrical set and hysteresis. © 2017 Society of Chemical Industry