Performance analysis of MWCNT/Epoxy composites produced by CRTM

In the present work, carbon fiber reinforced polymer laminates were manufactured by means of Compression Resin Transfer Molding using a commercial epoxy resin additivated with Multi Walled Carbon Nanotubes to impregnate a carbon fiber fabric. The weight loads of nanotubes investigated were equal to 0.5 and 1%. As a comparison, composite laminates were also obtained using the pristine resin. The same process parameters were used to manufactured additivated and unadditived composites. The presence of nanotube agglomerates and the filtering effect of the carbon fiber fabric during the resin flow into the mold were investigated by means of Dynamic Light Scattering and microscopic techniques. In addition, Differential Scanning Calorimetry was used to analyze the polymerization reaction and to measure both the glass transition temperature of nanoadditivated matrices and the apparent viscosity. Viscosity was measured through rheological analysis. Mechanical tests were carried out on samples obtained from additivated and unadditivated laminates. It was shown that the apparent viscosity of the additivated matrices tends to decrease as the shear rate increases, reaching values similar to those of the pristine resin at high shear rate. The polymerization reaction of the thermoset matrix is influenced by nanotubes, as well as the glass transition temperature which increases with nanotube weight load. The analysis of the laminates shows homogeneous dispersion of nanotubes, indicating that no filtering effect occurs. Finally, tensile and flexural tests show a reinforcement effect of nanotubes both on strength and stiffness of the composite.