Effects of Graphene Oxide-Carbon Nanotube Hybrids as Nanofiller on the Interfacial Interaction in Nylon 6,6 Prepared by In-situ Interfacial Polymerization

Abstract

Nylon 6,6 nanocomposites including well-dispersed graphene oxide (GO) and carbon nanotubes (CNTs) were successfully fabricated via in situ interfacial polymerization between two immiscible phases: organic phase assisted by poly(vinylpyrrolidone, PVP) surfactant containing adipoyl chloride with dispersion of GO and CNTs; aqueous phase containing hexamethylenediamine. Prior to the polymerization, GO was functionalized with thionyl chloride, resulting in acyl-chloride-functionalized GO (AGO). The effects of incorporation of AGO and PVP on the state of dispersion were investigated. It was observed that the addition of AGO and PVP reduced particle flocculation, leading to a well-dispersed suspension as verified through dispersion stability analysis and UV–Vis spectroscopy. The interfacial interaction between the carbon nanofillers (AGO, CNTs) and nylon 6,6 chain can be induced via hydrogen and covalent bonding as confirmed using spectroscopic results. According to the analyses of thermal properties, nuclei crystallization in nylon 6,6 nanocomposites was promoted by the strong nucleating behavior of AGO and the thermal stability was improved. Tensile tests of the composite films (nylon 6,6/AGO, CNT) showed 122 and 152% increases in the tensile strength and modulus, respectively, as compared to the neat polymer. This suggests that the interfacial interaction between nylon 6,6 and AGO/CNT contributes to enhanced load transfer in nanocomposites, thus enhancing the mechanical properties.