Preparation,characterization, and mechanical/tribological properties of polyamide 11/Titanium dioxide nanocomposites

In this study, the effects of the surface chemical modification of titanium dioxide (TiO₂) nanoparticles and their addition into polyamide 11 (PA11) on the mechanical, dynamic‐mechanical, and tribological properties of PA11/TiO₂ nanocomposites were investigated. To improve the interfacial adhesion between the nanoparticles and the polymeric matrix, the surface of TiO₂ nanoparticles was modified with 3‐aminopropyl trimethoxysilane (ATPMS). Nuclear magnetic resonance (NMR), infrared spectroscopy (IR), and thermogravimetric analysis (TG) were used to evaluate the efficiency of the surface chemical modification of TiO₂ nanoxide. PA11/TiO₂ nanocomposites with 2 and 4 wt% of TiO₂ were prepared in an internal mixer. The interfacial adhesion between the matrix and the TiO₂ was evaluated by dynamic‐mechanical analysis (DMA), and the dispersion of nanoparticles was analyzed by scanning electron microscopy (SEM). The NMR spectrum of the modified TiO₂ exhibited peaks in the region between ?55 ppm and ?70 ppm, indicating disubstituted and trisubstituted chemical structures between alkoxysilano structures and TiO₂. Nanocomposites with modified TiO₂ exhibited the lowest tan δ peak values, which provide evidence that the chemical modification of the TiO₂ facilitated energy dissipation at the interface of TiO₂ with the PA11 matrix. Surface modification of the TiO₂ nanoparticles with ATPMS caused a greater reduction of the mass loss by abrasion when compared with nonmodified PA11/TiO₂ nanocomposites; this reduction reached approximately 70% in comparison with the mass loss of neat PA11. POLYM. COMPOS., 37:1415–1424, 2016. © 2014 Society of Plastics Engineers