Effect of Filler Orientation on the Electrical Conductivity of Carbon Fiber/PMMA Composites
AbstractThe electrical conductivity of extruded carbon fiber (CF)/Polymethylmethacrylate (PMMA) composites with controlled CF aspect ratio and filler fractions ranging from 0 to 50 vol. % has been investigated and analyzed. The composites were extruded through a capillary rheometer, utilizing either 1-mm or 3-mm diameter extrusion dies, resulting in cylindrical composite filaments of two different diameters. Since the average CF orientation becomes more aligned with the extrusion flow when the diameter of the extrusion dies decreases, the relationship between conductivity and average fiber orientation could therefore be examined. The room temperature conductivities of the extruded filaments as a function of CF fractions were fitted to the McLachlan general effective medium (GEM) equation and the percolation thresholds were determined to 20.0 ± 2.5 vol. % and 32.0 ± 5.9 vol. % for the 3-mm (with CFs oriented less) and 1-mm (with CFs oriented more) filaments, respectively. It turned out that the oriented CFs in the composite shift the percolation threshold to a higher value, however, the conductivity above the percolation threshold is higher for composites with oriented CFs. A novel approach based on the Balberg excluded volume theory was proposed to explain this counterintuitive phenomenon. View Full-Text
Share & Cite This Article
Qu, M.; Nilsson, F.; Schubert, D.W. Effect of Filler Orientation on the Electrical Conductivity of Carbon Fiber/PMMA Composites. Fibers 2018, 6, 3.
Qu M, Nilsson F, Schubert DW. Effect of Filler Orientation on the Electrical Conductivity of Carbon Fiber/PMMA Composites. Fibers. 2018; 6(1):3.Chicago/Turabian Style
Qu, Muchao; Nilsson, Fritjof; Schubert, Dirk W. 2018. "Effect of Filler Orientation on the Electrical Conductivity of Carbon Fiber/PMMA Composites." Fibers 6, no. 1: 3.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.