IMPACT PROPERTIES IMPROVEMENT OF NANOCOMPOSITES USING VARIOUS CARBON NANOTUBES GEOMETRIES

The benefits of composites are diverse. They are mainly used for their lightweight and high specific strength properties. One of the main disadvantages is that composites can delaminate due to poor interlaminar strength, and a sudden impact can disintegrate the composite laminates. There are many classic techniques that have been used to overcome these issues, but the use of nanomaterials as an additional reinforcement to improve impact resistance properties has been extensively studied in recent times. In this study, an adequate number of flat square epoxy panels reinforced with carbon nanotubes (CNTs) were prepared per the ASTM standard D7136/D7136M−20. Three different geometries of multi-walled carbon nanotubes were used in this study: straight (MWSCNTs), helical (MWHCNTs), and OH-functionalized straight (FMWSCNTs). These CNTs were used as a nanoscale reinforcement in epoxy resin to fabricate nanocomposite samples. A drop weight test was performed, and all the fractured panels were visually compared against the neat epoxy sample results. Based on the total number of failed samples under a normalized impact energy of 0.335J/mm, it is observed that FMWSCNTs increase the impact resistance of epoxy panels at the greatest rate. Additionally, according to the number of observed cracks in the failed samples, straight CNTs and helical CNTs demonstrated a similar smaller improvement in impact resistance when compared to the neat samples.