Development of Highly Conductive Hybrid Composites

Electrically conductive plastic composites are developed to overcome the major shortcomings of naturally conductive polymers. Conductive plastic composites combine the properties of metals with the polymers. But the state of-the-art conductive plastics available in the market are also characterized by the short comings for example, the low electrical conductivity compared with the standard metallic conductors. This low conductivity of the materials is the bottleneck for many fascinating applications of the composites where they can provide lot of process and design related advantages. The work presented here attempts to overcome this short coming of the conductive composites by developing hybrid composites to enhance the conductivity network inside the polymer matrix. It discusses the on-going work on the development of the composite based on metal graphenehybrid system. The production and properties of novel composites based on Polyamide 6,Graphene nano-platelets (GNPs) and Cu fibers are discussed. The mechanical, electrical, and thermalproperties of the produced hybrid composites are studied. The influences of the factors like filler contents, filler characteristics, annealing etc. on the electrical, thermal, and mechanical properties of the composites are presented. The presentation discusses the underlying mechanisms responsible for the modulation inthe properties of the hybrid composites. Experimental work shows that the combination of GNPs and metallic micro fillers leads to significant improvements in thermal and electrical conductivities. To some extent GNPs acts as conductive bridges in minuscule gaps of the Cu fibers to increase the number of contacts in the constructed network. The combination of the two different fillers increased the mechanical properties up to 133 % compared to the metal reinforced composites indicating stronger interfaces between the fillers fillers and polymer matrix. Rheological investigations also confirm the effectiveness of hybridization. Furthermore, the influences of annealing on the conductivities of the specimens are studied. Adding an annealing step following the nanofiller inclusion within the metal filled composite resulted in 250 and 151 % enhancement in the thermal and electrical conductivities respectively.