Surface modification of Kevlar by grafting carbon nanotubes

A novel and efficient method was developed for surface-modification of Kevlar fibers by multi-wall carbon nanotubes (MWCNTs). Kevlar fibers were immersed in a solution mixed with Hexamethylene diisocyanate, 1,4-diazabi-cyclo [2,2,2] octane (DABCO), and toluene to introduce pendant amine groups before the COCl-functionalized carbon nanotubes were chemically grafted onto the surface of modified fibers under ultrasonic condition. The characterization of resulting fiber involved in SEM, infrared spectroscopy, and tensile measurement. Results indicated over 20% of the fiber surface were coated by MWCNTs even after washing, which indicated a good adhesion. Furthermore, the mean value of tensile strength of Kevlar fiber was improved by 12% compared with original one. And the interlaminar shear strength (ILSS) of the fiber-reinforced bismaleimides composite was increased by 30%.