Preparation and mechanical properties of MWCNT and carbon fiber reinforced bismaleimide resin composite

Bismaleimide reinforced with both MWCNTs and carbon fibers was prepared by mold-pressing carbon fiber paper stacks impregnated with a bismaleimide acetone solution containing MWCNTs grafted with ethylene diamine. The MWCNTs were oxidized by concentrated HNO3 to form carboxyl groups before grafting. Results show that the flexural modulus, flexural strength and impact strength of composite with a 0.5 mass% of MWCNTs is 43.85 GPa, 1 160.62 MPa and 28.50 kJ/m2, which represent increases of 49.56%, 17.41% and 19.65% respectively compared with the carbon fiber/BMI composite.