Kinetics of dynamic percolation in polymer/carbon composites

Dynamic percolation differs from static percolation in polymer composites owing to its occurrence at a particular filler fraction under thermal activation. Mechanistic insights into dynamic percolation might lead to develop polymer composites with controlled electrical properties at lower filler fractions and improved temperature coefficient of resistance phase transitions. Although attempts have been made to kinetically describe the dynamic percolation in polymer composites, a generalized mechanism-based approach has not yet been reported. In this article, a systematic and generalized theoretical approach to kinetically model the dynamic percolation in polymer/carbon composites has been put forward. Based on the proposed approach, a kinetic expression to predict the quasi-thermodynamic equilibrium state in a polymer/carbon composite at constant temperature is derived. The soundness of the proposed approach is justified by its effective applications on poly(vinylidene fluoride)/multiwalled carbon nanotube (PVDF/MWNT), poly(vinylidene fluoride)/carboxyl-functionalized MWNT (PVDF/MWNT), high-density polyethylene/carbon black, and poly(methyl methacrylate)/carbon black composites. Certain mechanistic complexities of dynamic percolation are also pointed out and discussed. POLYM. ENG. SCI., 2019. (c) 2019 Society of Plastics Engineers