High Performance Polymer Nanocomposites
S. Arzberger, R. Baughman
Composite Technology Development, US
Keywords: polymer nano composites high mechanical perfrmance
Abstract:Carbon nanotubes (CNT) offer the highest Young’s modulus (stiffness), thermal conductivity, electrical conductivity, and current density of any known material, while having a low density. As such, their inclusion as reinforcements in polymers holds tremendous potential for unprecedented structural efficiencies. However, to date, prior efforts have only realized a fraction of this potential. Under a Phase I STTR from the Office of Naval Research, Composite Technology Development, Inc. (CTD) and the University of Texas at Dallas (UTD) demonstrated the highest ever publicly reported mechanical performance from CNT polymer nanocomposites. The performance of these polymer nanocomposites approached those achieved with continuous carbon fiber polymer composites fabricated with intermediate modulus carbon fiber, such as IM7. Specimen fabrication has been accomplished using an established CFRP technique, with subsequent evaluation using a standard mechanical test method (ASTM D)3039). The processes used to fabricate these a continuous manufacturing process for ultrahigh-loaded CNT polymer nanocomposites has been conceptualized, with key demonstrations providing strong support for their economic production on a large scale. A summary of the Phase I STTR accomplishments include: • Demonstrated the use of CFRP fabrication techniques to fabricate unidirectional and quasi-isotropic ultrahigh-loaded CNT polymer nanocomposite ‘laminates’. • Established processing methods to achieve polymer nanocomposites with aligned CNTs and ultrahigh loading weight fractions ranging from 27 to 54 percent. • Established test methods to evaluate specimen mechanical performance based upon standard CFRP test methods using video image correlation (VIC) equipment to accurately measure stress and strain. • Demonstrated specific tensile strength and modulus values of approximately 0.8 and 80 GPa/(g/cc) (or nearly 50 and 75 percent, respectively, of the values known for intermediate modulus carbon-fiber, structural resin CFRP – 60-percent volume fraction) for unidirectional, ultrahigh-loaded CNT epoxy nanocomposites. • Demonstrated the feasibility of fabricating CNT sheet, structural resin prepreg materials. • Conceptualized and demonstrated key aspects of a continuous manufacturing process, which hold substantial potential for manufacturing scale-up and the fabrication of truly isotropic ultrahigh-loaded CNT polymer nanocomposites. • Established key end-user relationships with prime contractors. CTD and the University of Texas will be submitting a Phase II proposal for the continuation of this work. We are looking for collaborators, particularly those that are able to develop near term uses or applications for these materials.