Premium
Effect of shear on the electrical conductivity of suspensions of graphite in an unsaturated polyester resin
Author(s) -
Greenberg Ely R.,
May Michael N.,
Wise Jonathan,
GadalaMaria Francis
Publication year - 2005
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.20384
Subject(s) - materials science , composite material , shearing (physics) , graphite , electrical resistivity and conductivity , shear (geology) , electrical conductor , conductivity , anisotropy , polyester resin , polyester , chemistry , physics , quantum mechanics , electrical engineering , engineering
The effect of shear on the electrical conductivity of suspensions of conductive graphite particles in a nonconductive unsaturated polyester resin was investigated. At graphite loadings near 30 wt% the electrical conductivity was higher when the suspension was undergoing shear than when shearing stopped. Moreover, shearing caused a large permanent increase in the electrical conductivity of the suspension. When shear was restarted after a period of rest the transient response of the electrical conductivity depended on the direction of previous shear, indicating that the suspension acquires an anisotropic structure under shear. The transition upon shear reversal was strain‐dependent. Surprisingly, at graphite loadings near 50 wt% the effect of shear on the electrical conductivity was the opposite of that at loadings near 30 wt%. At intermediate loadings the effect of shear on the electrical conductivity was less clear. The results may have applications in the manufacture of composite bipolar plates for fuel cells and of various other parts made from conductive polymers. POLYM. ENG. SCI., 45:1540–1545, 2005. © 2005 Society of Plastics Engineers