Effects of chemical structure and morphology of graphene-related materials (GRMs) on melt processing and properties of GRM/polyamide-6 nanocomposites

• Main Authors: Julio Gomez, Elvira Villaro, Panagiotis G. Karagiannidis, Ahmed Elmarakbi
• Format: Article
• Language: English
• Published: Elsevier 2020-09-01
• Series: Results in Materials
• Subjects: Graphene; Graphene oxide; Reduced graphene oxide; Functionalisation; Polyamide-6; Polymer nanocomposites
• Online Access: http://www.sciencedirect.com/science/article/pii/S2590048X20300479

In this work, different graphene-related materials (GRMs) and polyamide-6 (PA6) were melt compounded by twin screw extrusion. The GRMs prepared were graphene nanoplatelets (GNPs), graphene oxide (GO), reduced graphene oxide (rGO) and silane functionalised reduced graphene oxide (f-rGO). The GRMs had comparable lateral size (20–30 ​μm), but different thickness and surface chemistry which resulted in different behaviour in processing of melt flow, maximum loading in the PA6 matrix (15%wt for GNPs, 10%wt for GO, 2%wt for rGO and 2.5%wt for f-rGO) as well as mechanical properties. A second extrusion phase produced formulations with lower concentration of GRMs. In the case of f-rGO/PA6, the melt flow index increased by over 76% at 0.5%wt loading compared with the pure PA6 resin, facilitating processing and dispersion of the flakes within the matrix and increasing the Young´s modulus (E) and tensile strength by 39%. However, high filler content above 10% has been achieved only for GNPs improving the Young´s modulus by 50% at 15%wt.