Investigation of properties of nano-silica modified epoxy resin films and composites using RFI technology

The carbon-fiber-reinforced composites modified by nano-silica were successfully prepared using RFI technology. And the properties of composites also were studied. The investigations revealed that the properties of composites were increased by filling nano-silica. With the increase of nano-silica content, the density of carbon-fiber-reinforced composites was increased, while the glass transition temperature, tensile strength and flexural strength were first increased and then decreased. At the nano-silica content of 3 wt%, the glass transition temperature reached a maximum of 117.3 °C. When the nano-silica content was 4 wt%, the tensile strength and flexural strength were increased to 595.69 and 703.76 MPa, which were improved by 86.30% and 126.98% compared with the composites without nano-silica. Therefore, the best properties of carbon-fiber-reinforced composites was obtained with filling 4 wt% nano-silica content, while the toughening and strengthening effect was optimal, since nano-silica as a reinforced material were filled the gap between epoxy resin and carbon fiber to disperse the external force.