Effect of uniaxial pressure on conduction behavior of carbon black filled poly（methyl vinyl siloxane） composites

~~Effect of uniaxial pressure on conduction behavior of carbon black filled poly(methyl vinyl siloxane) composites1. Lundberg, B., Sundqvist, B., Resistivity of a composite conducting polymer as a function of temperature, pressure, and environment: Application as a pressure and gas concentration transducer, J. Appl. Phys., 1986,60(3): 1074-1079. 2. Carmona, F., Canet, R., Delhaes, P., Piezoresistivity of heterogeneous solids, J. Appl. Phys., 1987, 61(7): 2550-2557. 3. Pra…

Effect of uniaxial pressure on conduction behavior of carbon black filled poly(methyl vinyl siloxane) composites

The piezoresistive behavior of carbon black (CB) filled poly(methyl vinyl siloxane) (PMVS) vulcanites under uniaxial compression was studied. At filler weight fractions φ slightly above the percolation threshold φ_c, resistance first increased with pressure and then turned to decrease at a critical compressive stress, exhibiting a positive pressure coefficient of resistance (PPCR) and a negative pressure coefficient of resistance (NPCR) effects, respectively. The NPCR effect became much more pronounced at φ ≫ φ_c, while compressive cycles facilitated the occurrence of the weak PPCR effect during compression. The PPCR-NPCR transition was a process related to true stress. It is believed that the changes of microstructure in the percolating network, i.e. the breakdown and the reformation of infinite conducting clusters, under pressure would be responsible for the uniaxial piezoresistance and the plastic deformation of the filled vulcanites.