Preparation and characterization of high performance of graphene/nylon nanocomposites

The potential of using functionalized graphene (FG) as reinforcement for producing high performance of nylons 11 and 12 nanocomposites was explored. A series of FG/nylons 11 and 12 nanocomposites fabricated by a direct melt blending with assistance of pre-mixing was assessed for their mechanical and barrier properties as a function of FG loading. The results revealed that the ultimate tensile strength, elongation at break, impact strength, toughness and permeation resistance characteristics were improved by the incorporation of a very small amount of the FG into the nylon matrices. In the nylon12, the ultimate tensile strength increased by similar to 35%, elongation at break by similar to 200%, fracture toughness by similar to 75% and the impact failure energy by similar to 85%, respectively, when only 0.6 wt% FG was incorporated. In contrast, the tensile mechanical properties and fracture toughness of the nylon11 was only slightly improved by addition of FG, but a dramatic enhancement of similar to 250% in impact strength was achieved by adding 1 wt% FG. In addition, the graphene sheets were dramatically effective for improvements of vapor and gas barrier properties for both nylons at a very significant low loading. Especially, the nylon11 films with FG loading as low as 0.3 wt% showed a superior to reduction of water vapor and oxygen permeability by similar to 49% and similar to 47%, respectively. In this communication, the effects of FG on these property enhancements of the nylons have been well discussed. It can be concluded that to achieve the maximally improved properties, aside from good dispersion of the filler, strong interface between the polymer and graphene sheets, flexibility of graphene in the polymer matrix could be considered to be also an important factor due to the characteristics of graphene wrinkled structure in the polymer matrix. (C) 2013 Elsevier Ltd. All rights reserved.