Multi-scale hybrid polyamide 6 composites reinforced with nano-scale clay and micro-scale short glass fibre

Multi-scale reinforcements consisting of clay and short glass fibre (SGF) filled polyamide 6 was prepared by a two-step melt compounding process in a twin-screw extruder. Morphologies of clay in PA matrix were observed via a transmission electron microscope (TEM), while the fracture surfaces of PA/clay/SGF were observed via a scanning electron microscope (SEM). Dynamic mechanical properties and thermal expansion behaviours were measured using a dynamic mechanical analyser (DMA) and a thermal mechanical analyser (TMA). The synergy of multi-scale reinforcements of clay and glass fibre provided better physical properties for polymer-matrix composites (PMCs) than each of individual filler. Clay and glass fibre synergistically improved char formation and reduced the flammability of PA/clay/SGF. Rheological properties of PA/clay/SGF under dynamic and steady shear were evaluated. The Herschel-Bulkley model was applied to predict the effect of two fillers on the viscosity and the yield stress. (C) 2013 Elsevier Ltd. All rights reserved.