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A comparative phenomenological modeling analysis in the AC electrical conductivity of polypropylene melt-mixed with pyrolytically stripped Pyrograf® III carbon nanofiber composites
Authors: Aribou, N.; Nguyen, Q.; Silva, Jaime; Tavares, C.J.; Paleo, A.J.
Ref.: Funct. Compos. Struct. 8(3), 035008 (2026)
Abstract: In this study, a variation of the generalized effective medium (GEM) and the mixing rule (MR) models, taking into account the interphase, is proposed to the AC electrical conductivity ( (sigma AC) of polypropylene (PP) composites prepared by melt-mixing with 0-2.4 vol. % of Pyrograf (R) III PR 25 PS XT carbon nanofibers (CNFs). An onset of conductive network formation is found at CNF concentration of 0.9 vol. %, and the sigma AC reaches similar to 1 & times; 10-8 S m-1 at 200 Hz at the highest concentration of CNFs (2.4 vol. %), suggesting that the latter PP/CNF composites are suitable as static dissipative materials. It is inferred from the modified GEM and MR models that, in the same way as the sigma AC of the PP/CNF composites, the interphase electrical conductivity ( sigma int) increases with frequency. On the contrary, the interphase-related volume constant (k) decreases with frequency. Furthermore, although the interphase volume fraction (phi int) shows a linear dependence on CNF content, it tends to decrease as the frequency increases. Both observations infer that as frequencies increase, interphase-related effects on sigma AC become less evident.
