Abstract
DC and AC electrical conductivity and electromagnetic interference shielding effectiveness of milled carbon fiber/nylon composites were investigated with the kind of nylon matrix. Percolation transition at which the conductivity is sharply increased was observed at about 7 vol% of milled carbon fiber. Nylon 46 as a matrix was more effective to obtain high electrical conductivity than nylon 6, and the difference in conductivity was occurred by the treatment of coupling agent. Frequency dependence of AC conductivity could be explained by relaxation phenomenon at just below percolation and resonance phenomenon at 40 vol% of carbon fiber, respectively. Negative temperature coefficient phenomenon was found in all composites. Electromagnetic interference shielding effectiveness was increased with the concentration of carbon fiber. At a high conductivity region the return loss was more dominant to the total shielding effectiveness than the absorption loss.
Original language | English |
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Pages (from-to) | 201-209 |
Number of pages | 9 |
Journal | Polymer (Korea) |
Volume | 27 |
Issue number | 3 |
Publication status | Published - 2003 May |
Keywords
- Electrical conductivity
- Electromagnetic interference shielding effectiveness
- Milled carbon fiber/nylon composites
- Percolation
- Return loss
ASJC Scopus subject areas
- General Chemical Engineering
- Polymers and Plastics
- Materials Chemistry