(80e) Enhanced Melt Processing of Conductive Polymer Composites for Use In Multilayer Coextrusion

Multilayer coextrusion combines multiple polymers in a layered structure to produce properties that are not found in a single polymer. For many potential applications one or both of the layers needs to include large volumes of filler. Amongst the desired properties, one of the largest challenges is to obtain conductivity within an individual layer. Traditionally, conductive polymer materials have been difficult to melt process. Inherently conductive composites will often degrade before melting or have a high viscosity as a result of a rigid backbone. Conductivity as the result of added filler requires high loadings that can significantly increase the viscosity. In addition, as the number of layers increases the layer thickness will decrease to below a micron. At reduced layer thicknesses the filler must be on the nanometer size scale that will have a more pronounced impact on the viscosity relative to larger fillers. High viscosities in coextrusion are problematic because a viscosity mismatch between layers can produce layer breakup. As a result, we have developed several strategies to produce conductive materials that have a reduced impact on the viscosity to aid in the production of filled multilayer structures by coextrusion.