Abstract

This thesis was based on the research on the nanocomposites fabricated from TGDDM/DDS epoxy system, carbon fiber reinforcement, and montmorillonite nanoclay modifier. The viscosity and gel time of nanoclay-filled composites with different nanoclay contents were measured. The influence of nanoclay on curing process was investigated by DSC testing. High quality carbon fiber-reinforced nanocomposites were manufactured through lay-up plus autoclave process. The nanocomposites had uniform fiber volume fraction, fewer dry spots, and fewer resin-rich areas. The plain-strain fracture toughness of nanoclay-filled epoxy composite was measured by single-edge-notch bending testing. The testing results indicated that both the critical-stress-intensity and the critical strain energy release rate were dramatically augmented owing to the introduction of nanoclay. The interlaminar fracture toughness of carbon fiber-reinforced composites was evidently increased with the introduction of nanoclay. The fracture surface of nanoclay-filled samples exhibited relatively rougher feature, compared to the featureless fracture surface of pristine epoxy system. Small amount of nanoclay (2 phr) can significantly enhance the flexural strength and modulus of the composites. The fire resistance of epoxy composites was enhanced due to the addition of nanoclay via the limiting oxygen index experiment and TGA testing. An evident augmentation of thermal shock resistance was obtained with the addition of nanoclay.