Synergistic reinforcing and toughening of polydicyclopentadiene nanocomposites with low loadings vinyl-functionalized multi-walled carbon nanotubes

Synergistic reinforcing and toughening of polydicyclopentadiene (PDCPD) nanocomposites reinforced with multi-walled carbon nanotubes (MWNTs) were achieved and enhancing mechanism was investigated. MWNTs were functionalized with vinyl groups via chemical grafting and the vinyl groups functionalized MWNTs (f-MWNTs) were characterized by fourier transform infrared spectroscopy and field-emission scanning electron microscopy. The mechanical properties of f-MWNTs/PDCPD composites were investigated by means of universal testing, notched izod impact testing and dynamic mechanical analysis . Synergistic improvement of yield strength, tensile toughness and impact strength of composites were observed with the incorporation of 0.1–0.4 wt% f-MWNTs compared with pure PDCPD. The maximum yield strength, toughness and impact strength of the composites increased by about 48%, 94% and 97%, respectively. The simultaneous enhancement is probably ascribed to MWNTs’ excellent mechanical properties and high aspect ratio, short and flexible vinyl groups onto MWNTs surface, strong covalent bonds between PDCPD and f-MWNTs.