Desenvolvimento de nanocompósitos de poliamida 6 com argila organofílica.

Abstract

Nanocomposites of polyamide 6 with organoclay have been prepared by melt intercalation method. The properties that were studied: processing variables (speed and configuration of screw and feeding rate); three molecular weigth of the polyamide 6 matrix and two clay quantities (3 and 5%) in obtaining nanocomposites with organoclay and their properties. The clay used in this research was treated with quaternary ammonium salt (Cetremide) and was characterized by x-ray fluorescence (FRX), spectroscopy in the infrared region by Fourier transform (FTIR), termogravimetry (TG) and x-ray diffraction (XRD). The results showed the incorporation of salt in clay and its organofilization. For obtaining nanocomposites, they were prepared concentrates of PA6/clay (1: 1) and these were added in polyamide 6 in quantities necessary to achieve nominal contents 3 and 5% by weight clay, using a twin screw extruder corrotational. Subsequently, the samples were molded by injection and characterized by: capillary reometry, TG, XRD, differential scanning calorimetry (DSC), mechanical tests (impact and tension), heat deflection temperature (HDT), dynamic-mechanical thermal analysis (DMTA) and transmission electron microscopy (TEM). The results of capillary reometry showed that the presence of organoclay on PA6 increased viscosity of the systems. By XRD and TEM, it was seen that all systems have predominance of exfoliated and/or partially exfoliated structure. The DSC results showed the formation of the phases (a and y) and increasing the crystallinity degree of the nanocomposites in relation to the pure polymer. The mechanical properties under traction and thermomechanical (HDT), have been improved significantly when compared to the properties of polyamide 6. The analysis by DMTA revealed that the incorporation of organoclay, in polymeric matrices of polyamide 6, increased the rigidity of the system (E") and decreased the tan 8, for all temperatures, confirming the reinforcing effect of the clay in the polymer.