This Small Business Innovation Research Phase I project will experimentally and theoretically investigate the development of a new class of electrically conductive and structural engineered polymeric matrix composites (PMC). This will be preformed using single and/or multi-wall nanotubes as the reinforcing phase to provide or significantly augment their properties. In addition to homogeneous PMC, the program will investigate nanotubes as a selective structural reinforcement in critical areas of a component. Because of their dimensions, metallic character and electron emission properties, they could be effective at reflecting electromagnetic radiation particularly at high frequencies and high energy. The program will investigate the effect of concentration and processing variables on the ability of these small structures to function in the dielectric polymeric matrix. Because of their high elastic modulus, nanotubes could provide superior mechanical reinforcement at lower concentrations. Discontinuous reinforcements (nanotubes and, where useful, synergistic reinforcements such as chopped carbon fibers) will first be homogeneously dispersed and then rigidized in this configuration. The preform can be fully characterized before the polymer matrix is introduced allowing for superior quality control and assurance that design properties are achieved before the matrix is added. The preform will then be filled with a polymeric matrix using vacuum assisted resin transfer molding.
Both military and commercial regulations require EMI shielding of every electronic component. However, in comparison to metallic packaging, there is more part to part variability in PMC components made conductive by inclusion of conductive fillers,particularly at the low concentrations anticipated for nanotubes. Automated manufacture and testing of fibrous preforms prior to introduction of the matrix will significantly reduce the potential for variability and thus hasten the acceptance of lightweight PMC components. Inexpensive, reliable conductive plastic components can also be used in major electrically dissipative applications as electrostatic charge dissipation, electrostatic painting and conductive flooring. In addition, lightweight homogeneous and selectively reinforced lightweight PMC's will find use in a wide variety of military and industrial applications.