Rheological methods to investigate graphene/amorphous polyamide nanocomposites: Aspect ratio, processing, and crystallization

Abstract

Nanocomposites obtained by melt mixing commercial graphene in an amorphous polyamide are investigated. No symptoms of percolation are observed, which is attributed to the low aspect ratio (fs = 20) deduced from elastic modulus data. The study of the effect of temperature and pressure on viscosity, carried out combining extrusion rheometry and PVT tests, reveals that the nanocomposites can be extruded and injected under similar conditions to pure polyamide. The time evolution of the dynamic viscoelastic functions are analyzed to investigate the crystallization process, observing that it is considerably accelerated in nanocomposites. The results represent a valuable outcome for practical applications.