On the processing and properties of carbon nanofiber reinforced hybrid structural composites

Structural composites based on unidirectional E-glass and epoxy have been fabricated through resin film infusion. Low weight fractions of carbon nanofibers are dispersed in epoxy resin using a solvent-assisted ultrasonication process. Rheological characterization of carbon nanofiber-filled epoxy revealed that viscosity, and in turn processing characteristics of the resin remain almost unaffected as compared to the pristine resin system at elevated temperature of composite processing. Glass transition temperature of epoxy showed a considerable improvement with carbon nanofibers. Local flow of the modified resin through the embedded fabric plies in the resin film infusion process made sure that a uniform distribution of nanoparticles is achieved throughout the composite. Compressive strength of hybrid composites showed over 40% increase while interlaminar shear strength improved by 33% with carbon nanofibers at a loading fraction as low as 0.5 wt%.