Importance of Concomitant Strengthening and Toughening in Nanoclay Reinforced Polymers

Fracture properties and deformation mechanisms of nanoclay reinforced polypropylene (PP) modified with maleic anhydride were investigated. Elastic-plastic fracture mechanics was employed to characterize the toughness in light of substantial post-yield deformation for the reinforced maleated PP. Upon introduction of 2.5 wt% clay loading, it was observed that tensile strength, modulus and fracture initiation toughness concomitantly increased substantially. Continued increase in clay loading only led to stiffening and strengthening effects to the detriment of fracture toughness. Deformation mechanisms were examined using electron microscopy and small angle X-ray scattering