Electrical and damping behaviors of CPE/BaTiO3/VGCF composites

The electrical and damping behaviors of chlorinated polyethylene (CPE)/barium titanate (BaTiW/vapor-grown carbon fiber (VGCF) composites have been investigated. CPE/BaTiO3/VGCF composites exhibit a lower percolation threshold compared to the CPE/VGCF two-component system. This can be attributed to the presence of BaTiO3 particles, which increases the effective concentration of VGCF in the composites. For CPE/BaTiO3/VGCF composites, the dynamic mechanical analysis shows that, at the glass transition temperature of CPE, the values of loss factor decrease with increasing VGCF content. However, within the room temperature region (around 25 degrees C), the values of loss factor for CPE/BaTiO3/VGCF samples are higher than that of CPE/BaTiO3 and present a peak at 8 vol.% VGCF content, which corresponds to the beginning of the second percolation stage. This may imply that the piezo-damping effect is directly related to conductive network formation in the composites and a new damping material with both a higher loss factor value and efficient stiffness in the region of practical temperature can be obtained by changing the composition of the CPE/BaTiO3/VGCF composites. (C) 2005 Elsevier B.V. All rights reserved.