Investigation On Conductive Properties Of CNT/EP Composite

Caron nanotubes (CNTs) exhibit an excellent mechanical properties; the super high tensile strength, toughness and Young's modulus; and a unique microstructure; high specific surface area and high aspect ratio, with many unique chemical and physical properties, carbon nanotubes(CNT) are of great interest for many potential applications in various fields. On the other hand, electronically conducting polymers have also attracted much attention for their excellent prosperities: with the electricity and optics prosperities of metal and inorganic semiconductor, with mechanical and easy-shaped prosperities of organic polymer, and electrochemistry oxidative and reductive prosperities.The MWNTs used in this paper were produced by chemical vapour deposition method. MWNTs via oxidation and purification, and mechanical milling, sonication, microwave treating, high speed shearing and with dispersant to treat the surface of them, the CNTs/Epoxy resin (EP) composite was prepared by casting method. The result proved that treated carbon nanotube had a more homogenous distributing in the composites. The electrical properties and the relationship between microstructure and properties of the composites were investigated by SEM, HRSEM and high resistance voltmeter.The results indicated that: With air oxidation and acid oxidation we can successfully get CNTs with higher purity (>90%). mechanical milling and sonication can disperse CNTs uniformly in EP, when the ratio of CNTs and EP was 1%, the surface resistivity is 10¹¹Î©/sq, the ratio was 2%, the surface resistivity was 10⁹Ω/sq, it's three magnitude lower than pure EP. While the ratio was 6%, surface resistivity was 10⁵Ω/sq, this value had met the request of conducting polymer. The distributing was better when provided assistant of microwave treating, high speed shearing and different dispersants, and SEM photos also indicated better distributing, high resistance voltmeter measured the conductivity was higher.The content of CNTs was 3%, surface resistivity was 10⁹Ω/sq when only mechanical milling and sonication. While CNTs were treated by microwave in air 3min the resistivity was 10⁷Ω/sq, two magnitudes were lowered. Rotate speed was 6000r/min, shearing time was 10 min, the resistivity was 10⁵Ω/sq, three magnitudes were lowered. After single dispersant treating the surface, the ratio of dodecyl benzene sodium sulfonate and octadecanol was 0.8% and 0.7%, the surface resistivity all was 10⁶Ω/sq. While different dispersant mixed, the dispersion was better, Among them oleic acid and octadecanol mixed together, the result was best, it's 10⁵Ω/sq.