Volume resistivity of carbon-fibre-filled epoxy-resin under shear flow

✍ Scribed by Funabashi, Masahiro

• Book ID: 101229277
• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 307 KB
• Volume: 45
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199803)45:3<303::aid-pi935>3.0.co;2-x

✦ Synopsis

The volume resistivity of carbon-Ðbre-Ðlled epoxy-resin samples under shear Ñow was investigated by a rheometer with double cylindrical sample cells. The outer and inner cells were also used as electrodes. E †ects of shear rate and Ðbre content on the resistivity were investigated. These results were compared with those of carbon-Ðbre-Ðlled silicone-oil samples. The volume resistivity showed a minimum value at a characteristic shear rate. In order to explain the experimental results, the shear rate indicating minimum resistivity was assumed to be a characteristic shear rate, where carbon Ðbre formed the densest network structures. When the shear rate was lower than the characteristic value, the resistivity decreased with increasing shear rate, due to the increase in frequency of forming and breaking up of electrical networks made by the Ðbres. The resistivity increased with increasing shear rate, when it exceeded the characteristic value because of Ðbre alignments parallel to the electrode. These assumptions were conÐrmed using epoxy-resin samples Ðlled with carbon Ðbres, whose volume resistivity can be measured over a wide range of shear rate. The maximum volume fraction of Ðbres for epoxy-resin samples was greater than that for silicone-oil systems because of the di †erence between the viscosity of epoxy resin and that of silicone oil.

1998 SCI.