A review of conductive polymer composites filled with low melting point metal alloys

Abstract

Metal alloys with low melting temperatures may be blended into polymers to improve their electrical conductivity. We review the preparation, morphology, and electrical conductivity of polymer composites based on low melting point metal alloys, with or without additional filler particles. Since such alloys can be liquid under melt processing conditions, the composite morphology is determined by phenomena such as coalescence of liquid metal drops, orientation of the liquid metal phase, or selective wetting of a second filler by the liquid metal. None of these phenomena appear in conductive composites based on more common conductive fillers such as carbon black, carbon nanotubes, or metal particles. The published literature suggests that composites based on low melting metal alloys, with or without additional non-melting filler particles, can have much higher percolation thresholds and much higher electrical conductivity (∼1,000 S/m) than those based on fillers such as carbon black or carbon nanotubes. Changes in other properties such as rheological or mechanical properties are also discussed. POLYM. ENG. SCI., 58:1010–1019, 2018. © 2017 Society of Plastics Engineers.