Novel Polymer Nanocomposite Processing

72212-The uniform dispersion of nanoceramic filler particles within a polymer matrix, for producing high quality polymer/ceramic nanocomposites, is a very time-and energy-intensive process. The development of efficient methods for uniformly dispersing nanoceramic inclusions, which are well-adhered to the polymer throughout the polymer matrix, and for fabricating parts from such composites at low cost are significant challenges. This project will develop technology for achieving immediate and complete dispersion of the ceramic, by utilizing micron-sized polymer particles that have been individually pre-coated with a nanometers-thick ceramic layer. As a starting point for the nanocomposite formation, the pre-dispersed ceramic at the micron lengthscale will be intimately dispersed within the matrix. In Phase I, LDPE (low density polyethylene) and HDPE (high density polyethylene) polymer particles were coated with conformal, well-bonded, alumina nanocoatings of varying thicknesses (between 0.6 and 10 nm), the nanocoated polymer particles were extruded into test samples, and test samples were analyzed the by microscopy. The analysis revealed disperse micron sized aggregates of submicron alumina particles. A pilot plant was preliminarily designed and full scale costs were estimated to be less than $1/kg for the nanocoating process. Phase II will develop and optimize pilot scale facilities for coating on kilogram scales, required to fully test the materials for barrier properties. Other polymeric substrates will be investigated to broaden the range of applications for this novel nanocoating technology. Commercial Applications and Other Benefits as described by awardee: The process should be easily placed in an existing production line for the millions of tons of polymers made by gas phase polymerization. The process would conveniently fit between an existing gas phase fluidized bed polymer particle synthesis process and the extruder for making pellets. Applications include the replacement of metals and co-polymers with more easily recycled and lightweight nanocomposites.