Continuous Preparation of Polymer Nanocomposites for Applications in Novel Substrates, Multilayered Materials, and 3D Printing

C. Barry, D. Kazmer, J. Mead
University of Massachusetts Lowell,
United States

Keywords: nanocomposites, twin screw extrusion, injection molding, extrusion

Summary:

Polymer nanocomposites are composed of a nanofiller, such as nanoclay, carbon nanotubes, graphene, and nanosilver, in a polymer matrix. Depending on the choice of filler, these nanocomposites exhibit unique material properties, including improved barrier properties, flame retardance, mechanical properties, and electrical properties. The critical barrier to obtaining optimal properties is the need for excellent dispersion of the nanofiller throughout the polymer matrix and retaining this dispersion during subsequent melt forming processes. This paper (1) reviews experience with industrially-relevant, continuous melt mixing processes, specifically twin screw extrusion, in creating nanocomposites with low filler loadings, (2) recent efforts in extending melt mixing methods to polymer systems with high loadings of nanofillers, and (3) issues when melt mixing of nanocomposites with a high speed twin screw extruder. Also discussed in the behavior of these nanocomposites in commercial-scale melt forming processes, specifically extrusion of multilayer films, extrusion of novel filament for 3D printing processes, and injection molding of 3D parts