Effect of graphite nanoplatelets on the structure and properties of PA6-elastomer nanocomposites

Abstract

The combination of polymer blending and nanocomposite concepts represents a progressive approach to meet the increasingly high requirements of the properties of materials for different applications. This work addresses the reinforcement and structure-directing effects of graphite nanoplatelets (xGnPs) added into a Polyamide 6 (PA6)/elastomer system. Three different elastomers were used: an ethene-propene copolymer (EPR), an ethene-methacrylate copolymer (EMA), and an aminated polybutadiene (ATB). The addition of xGnP caused a reduction in the size of the EPR, EMA and ATB domains; the most significant size reduction was observed for EPR, which had the lowest compatibility with the polymer matrix. The xGnP was primarily located in the PA6 phase due to the presence of epoxy groups on the surface of the xGnP, which promoted the affinity to the PA6 matrix. At the same time, the content of the epoxy groups is low enough to achieve sufficient modification of xGnPs, e.g., with alkyl amines (∼6%), thus providing compatibility with nonpolar EPR. The evaluation of the mechanical parameters indicates that the combination of elastomers and xGnP leads to a polyamide material with enhanced strength, stiffness and toughness. Finally, it may be expected that the analogous graphene oxide, which has a higher potential for modification and finer platelets, will be a more effective nanofiller.