Effect of Melt Mixing on Electric Conductivity of Vapor Grown Carbon Fiber/Polycabonate Composite II
Yasuda, Takeshi / Takahashi, Tatsuhiro / Yonetake, Koichiro / Koyama, Kiyohito / Takahashi, Koji
Vapor Grown Carbon Fiber (VGCF) is, due to its extraordinary electrical properties, a most promising filler for researchers in polymer composites, which are mostly prepared through melt mixing. However, little is known about the effects of melt mixing conditions on the electric conductivity and rheological properties of composite. Here, we have measured electric conductivity, SEM observations and rheological properties in VGCF/polymer composite by varying melt mixing conditions.
We used a batch type twin-screw kneader, to prepare VGCF/PC composites at 260°C and 300°C by varying VGCF concentration, mixing time, and screw speed. The percolation property as a function of concentration was strongly affected by mixing time. When the mixing time became longer, the electrical surface resistivity increased at each concentration. When the screw speed became faster at a constant concentration, the surface resistivity increased and then reached a saturated value. A systematical understanding about the effect of mixing on electrical conductivity and rheological properties for VGCF/PC composite was presented.
Key words: Vapor Grown Carbon Fiber / Nano Composite / Electric Conductivity / Mixing Conditions / Rheology