Effect of nucleating agent on the nonisothermal crystallization kinetics of glass fiber- and mineral-filled polyamide-6 composites

Abstract

In this study, nonisothermal crystallization kinetics of glass fiber (GF) and clay-type mineral (MN)-reinforced polyamide-6 (PA6) composites prepared in a twin screw extruder were investigated by differential scanning calorimetry method in the presence and absence of an organic nucleating agent (NA). Kinetic parameters for the nonisothermal melt-crystallization process of samples were determined with several models namely Ozawa, Avrami, Jeziorny, and LiuMo. Crystallization rate parameters of the samples and nucleation activity of the fillers and additives were also calculated by the models suggested by Zhang and Dobreva and Gutzow, respectively. Crystallization activation energies of the samples were determined by the Kissinger model. It was found that the MN filler accelerates dramatically the crystallization rate of PA6 even without a NA. Small amount of NA also has a significant acceleration effect on the crystallization rate of PA6 composites. The rate acceleration effect of NA was found to be more pronounced in the composite sample reinforced with GF. Based on the kinetic study using of GF as major filler and small amount of clay-like MN in the PA6 composites could improve the mechanical properties and crystallization rate of injection-molded parts. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012