Mechanical properties and nonisothermal crystallization kinetics of polyamide 6/functionalized TiO₂ nanocomposites

Titanium dioxide (TiO₂) nanoparticles were pretreated with excessive toluene‐2,4‐diisocyanate (TDI) to synthesize TDI‐functionalized TiO₂ (TiO₂‐NCO), and then polymeric nanocomposites consisting of polyamide 6 (PA6) and functionalized‐TiO₂ nanoparticles were prepared via a melt compounding method. The interfacial interaction between TiO₂ nanoparticles and polymeric matrix has been greatly improved due to the isocyanate (NCO) groups at the surface of the functionalized‐TiO₂ nanoparticles reacted with amino groups (NH₂) or carboxyl (COOH) groups of PA6 during the melt compounding and resulted in higher tensile and impact strength than that of pure PA6. The nonisothermal crystallization kinetics of PA6/functionalized TiO₂ nanocomposites was investigated by differential scanning calorimetry (DSC). The nonisothermal crystallization DSC data were analyzed by the modified‐Avrami (Jeziorny) methods. The results showed that the functionalized‐TiO₂ nanoparticles in the PA6 matrix acted as effective nucleation agents. The crystallization rate of the nanocomposites obtained was faster than that of the pure PA6. Thus, the presence of functionalized‐TiO₂ nanoparticles influenced the mechanism of nucleation and accelerated the growth of PA6 crystallites. POLYM. COMPOS., 35:294–300, 2014. © 2013 Society of Plastics Engineers