Nonisothermal crystallization kinetics of ZnO nanorod filled polyamide 11 composites

Zinc oxide (ZnO) nanorods filled polyamide 11 (PA11) composites have been successfully prepared by melt-blending. Nonisothermal melt crystallization kinetics of PA11 and its nanocomposites is investigated using differential scanning calorimetry (DSC) under different cooling rates. With increasing the content of ZnO nanorods, the crystallization rate of PA11 decreases. The nonisothermal crystallization behavior was analyzed by Avrami, Ozawa and modified Avrami-Ozawa methods. It was found that the Ozawa method failed to describe the nonisothermal crystallization behavior of PA11 and ZnO composites. Avrami analysis reveals two liner regions for all cooling rates studied. In the primary crystallization process, the values of Avrami exponent n are about 3.4. And in the secondary crystallization, the n is about 1.8, which is characteristic of perfection of crystals. The combined kinetic method was able to describe the nonisothermal crystallization behavior of PA11 and its composites much effectively. In addition, the activation energies of nonisothermal crystallization are determined using Takhor model. The results show that the crystallization activation energy of PA11/ZnO composites is lower than that of neat PA11. (c) 2008 Elsevier B.V. All rights reserved.