Carbon Black as a Self-Diagnosing Probe To Trace Polymer Dynamics in Highly Filled Compositions

Abstract

A new technique for in situ studies on polymer dynamics in highly filled compositions was developed using carbon black (CB) as a self-diagnosing probe. It is based on the fact that CB particles dispersed in the polymer matrix are easy to aggregate and gradually form three-dimensional networks. Real-time monitoring of the dynamic process of the interparticle network formation was realized by tracing the time dependence of electrical resistivity during isothermal treatments. We investigated the influence of time, temperature, concentration, and the molecular weight of the polymer matrix on the dynamic percolation behavior and concluded that the percolation time when the electrical resistivity starts to decrease drastically is directly related to the zero-shear-rate viscosity of the polymer matrix. We also estimated the terminal relaxation time of polymer matrices from the dynamic percolation curves so as to eliminate the effect of CB concentrations. It is expected that the dynamic percolation measurements may provide an incisive method to study the influence of particle-polymer interactions on the relaxation and viscoelastic properties of a polymer matrix.

Morphology evolution, conductive and viscoelastic behaviors of chemically reduced graphene oxide filled poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) nanocomposites during annealing

“…Here, simultaneous measurements of conductive and rheological properties were preformed to trace the variation of volume resistivity  and dynamic modulus. (DC) percolation [68] . For PMMA/CRGO (100/0.2) nanocomposite, there is no initial plateau at the beginning of isothermal treatment, implying the conductive network of CRGO may form even in the sample preparation.…”

Rheological behaviors and electrical conductivity of long-chain branched polypropylene/carbon black composites with different methods

“…The research in dynamic rheological percolation is useful for learning the influence of dispersion and filler/ polymer interaction on the evolution of rheological percolation. On the other hand, conducting particles have been used as a self-diagnosing probe to trace the evolution of the rheological percolation involved in the viscoelasticity of the matrix [19].…”

Surface Morphology and Electron Transport Properties of Composite Films by Poly-N-vinylcarbazole/Polyaniline

“…Dispersion is a critical step because the resultant CPC can have very different electrical properties, depending on processing temperature, 5 blending time, 1 and particle/matrix interactions. 13,14 Controlling the effect of these parameters enables determining the appropriate balance between dispersion and aggregation phenomena to prevent the formation of micro-agglomerates or conductive pathway breakage. The wide choice of polymer/ filler combinations and the adjustment of conducting filler content (relative to percolation threshold) make numerous applications possible.…”