Damping Properties of Polyurethane/Epoxy Graft Interpenetrating Polymer Network Composites Filled with Short Carbon Fiber and Nano-SiO2

A series of short carbon fiber (CF) and nano-SiO2 filled polyurethane (PU)/epoxy resin (EP) graft interpenetrating polymer network (IPN) composites were prepared. The damping properties as well as tensile and impact strength of the IPN composites were studied systematically in terms of composition. Results revealed that the addition of short CF and nano-SiO2 can significantly improve the damping properties of pure PU/EP IPN, particularly at higher frequencies. Mechanical tests showed that the tensile strength of the IPN composites was improved after the incorporation of short CF and nano-SiO2, while the impact resistance of the composites was impaired after the addition of CF and higher content (beyond 1 wt%) of nano-SiO2. It is proposed that the CF and nano-SiO2 filled IPN composites would be useful as structural damping materials.