Structural Foaming at the Nano-, Micro-, and Macro-Scales of Continuous Carbon Fiber Reinforced Polymer Matrix Composites

Abstract

Abstract : The main objective of the project Structural Foaming at the Nano-, Micro-, and Macro-Scales of Continuous Carbon Fiber Reinforced Polymer Matrix Composites, was to create fractal structures within each composite lamina and introduce scaled porosity. As this fractal structure was being created, it was observed that the structure imitated that of naturally occurring bird feathers. Consequently, the name given to this new generation of fractal structured composite materials with scaled porosity was deemed Featherweight(trademark) Composites. The idea was to create lighter composites, and at the same time increase material strength. Through extensive characterization, two main interlayer enabling fractal systems were manufactured and characterized, first Carbon fiber - Epoxy Foam - CNTs, and second Carbon Fiber - Electrospun Nano-Fiber - CNTs, with both becoming transformed from the macro-, to micro-, and then nano-dimension. By focusing on low cost, the nano-materials utilized were not of the highest performance and quality. Nonetheless, with both interlayer systems, strength increased in several forms, such as fracture toughness (400%), stiffness (150%), flexural strength (80%), and tensile strength (20%), with percentages based on maximum values observed. At the same time, an experimental weight reduction of 10% was achieved. Finally, it is expected that if higher quality CNTs and matrix materials are used, the weight reduction can be higher, or even double that observed.