Influence of hybrid graphene oxide-carbon nanotube as a nano-filler on the interfacial interaction in nylon composites prepared by in situ interfacial polymerization

Abstract

Nylon 6,6 nanocomposites containing 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 polymerization, GO was functionalized with thionyl chloride, resulting in acyl-chloride-functionalized GO (AGO). The effect of incorporation of AGO and PVP on the state of dispersion was investigated. It was observed that the addition of AGO and PVP reduced particle flocculation, leading to a well-dispersed suspension as verified using dispersion stability measurement and UV-Vis spectroscopy. The interfacial interaction between the carbon nano-fillers and nylon 6,6 chain can be induced via hydrogen and covalent bonding between them. Thermal analyses revealed 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 increases of 122 and 152%, respectively, in the tensile strength and modulus 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 of the nanocomposites.