Effects of nanoparticle addition on the material properties of thermoset polymers will be investigated. The research has the specific focus on improvements in fracture toughness of an epoxy matrix. The matrix material is a toughened epoxy consisting of a resin phase of Diglycidylether of Bisphenol A (DGEBA) and a cycloaliphatic amine hardener. The nanoparticles used are ZnO ceramic particles, with a nominal diameter of 53nm. The nanocomposites were fabricated using a shear mixing device, and fracture toughness measurements using a four point bend apparatus were conducted on volume fractions ranging from 0-4%. A maximum increase in fracture toughness of 80% was achieved for 4 volume percent nanoparticle filler. It has been shown that the particle distribution can have a large effect on the mechanical properties of nanocomposites. Therefore, in an attempt to quantify the dispersion, the particle distribution was analyzed using a Focused Ion Beam. 5×5×3 micron three dimensional particle fields can be imaged using a procedure known as slice and view. It is thought that by increasing the fracture toughness of polymers, nanocomposites, in conjunction with fiber reinforcements, can be used in applications that require larger variations in temperature and strength. For instance, at the moment research is ongoing on the usage of composites in cryogenic hydrogen storage tanks. If the fracture toughness and permeability of composites can be improved, they can drastically reduce the weight of these tanks. The procedure in this presentation will be a first step in this process, and will be used in future work to investigate composites with both nanoparticle and fiber reinforcements.
