Impact fracture behaviour of nylon 6-based ternary nanocomposites

This study focuses on achieving high stiffness/strength and high fracture toughness in nylon 6/organoclay nanocomposites prepared via melt compounding by incorporating a maleic anhydride grafted polyethylene-octene elastomer (POE-g-MA) as a toughening agent. Mechanical test results indicated that the ternary nanocomposites exhibited higher stiffness than nylon 6/POE-g-MA binary blends at any given POE-g-MA content. More importantly, the brittle-ductile transition of nylon 6/POE-g-MA blends was not impaired in the presence of organoclay for the compositions prepared in this study. TEM analysis shows that organoclay layers and elastomer particles were dispersed separately in nylon 6 matrix. In the binary nanocomposite, no noticeable plastic deformation was observed around the crack tip. In the ternary nanocomposites, the presence of organoclay in the matrix provided maximum reinforcement to the polymer, while their absence in the elastomer particles allowed the latter to promote high fracture toughness via particle cavitation and subsequent matrix shear yielding. The partially exfoliated clay layers also delaminated and hence, adding to the total toughness of the nanocomposites.