Sandwich-structured starch-grafted polyethylhexylacrylate/polyvinyl alcohol thin films

Abstract

The present study aimed to explore the designing of nanoclay-decorated polyethylhexylacrylate/polyvinyl alcohol clay (S-g-PEHA/PVA@clay) thin films. The thickness of the S-g-PEHA/PVA@clay thin films mainly depends on the polymerization of ethylhexylacrylate and concentrations of PVA. The presence of clay nanoparticles in S-g-PEHA/PVA thin films was confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy analyses. The field emission scanning electron microscopy images showed the presence of exfoliated nanoclay throughout the films. High-resolution transmission electron microscopy was also performed to determine the degree of distribution and exfoliation of clay platelets. The surface and nano-tribological characteristics of the thin films were investigated by atomic force microscopy. It was found that the exfoliation and intercalation of clay platelets in thin films depend on the concentration of Cloisite ® 30B loading. The thermal conductivity, tensile strength, thermal properties, and refractive index were studied as a function of clay loading. It was noticed that tensile strength, thermal conductivity, thermal properties, and refractive index of the thin films were enhanced with the increase in Cloisite ® 30B content due to the formation of an exfoliated and partially intercalated structure of the S-g-PEHA/PVA@clay. Chemical resistance and antibacterial and biodegradable properties of the thin films were also studied. The oxygen barrier property of the thin films was reduced fivefold due to the sandwich structure of clay platelets.