Nylon 66 nanocomposites were prepared by melt compounding of nylon 66 with organically modified montmorillonite (MMT). The organic MMT was pre-modified with about 14 wt% of ammonium surfactant, much lower than the 35-46 wt% in most commercial organic MMT powders. Transmission electron microscope observation indicated that the MMT layers were well exfoliated in nylon 66 matrix.
Dynamic mechanical analysis confirmed the constraint effect of exfoliated MMT layers on nylon 66 chains, which benefited the increased storage modulus, increased glass transition temperature and reduced magnitude of alpha relaxation peak. The effects of organic MMT loading levels on reinforcement and fracture behaviour of the nanocomposites were evaluated using tensile and three-point bending tests.
The addition of the organic MMT clearly increased Young’s modulus and tensile strength but decreased ductility and fracture toughness of nylon 66.