Investigation of the alumina nanoparticle role in the enhancement of the mechanical properties of polyamide/polycarbonate blends

Abstract

In this work, we have investigated the effect of the incorporation of alumina nanoparticles on the mechanical properties of polyamide 6/polycarbonate (PA6/PC) blends. Nanocomposites were prepared through melt processing using both unreactive and reactive surface-treated alumina nanoparticles. Simple PA6/PC blend comprising 20 wt% of PA6 showed ductile mechanical behaviour with an ultimate elongation close to 50%. Contrarily, the incorporation of 20 wt% of PC into PA6 led to a drastic decrease of the strain at break (3%). A thorough study of the morphology, thermal and rheological properties pointed out that these poor mechanical properties were due to an autocatalytic thermal degradation of both PA6 and PC phases. Advantageously, the incorporation of 5 wt% of alumina nanoparticles, whatever their surface nature, significatively improved the tensile properties of the blends inducing an important increase in the elongation at break up to 88% when 5 wt% of hydrophilic alumina is used. Alumina nanoparticles proved to behave as protective agents for both PA6 and PC phases within the nanocomposite materials.