Improvements in the oxygen barrier property of polypropylene nanocomposites

Abstract

A nanocomposite consisting of polypropylene (PP)/nanoclay (montmorillonite) was prepared by means of a melt-compounding process with the use of a twin-screw extruder. Because of the complex dispersion of polar and hydrophilic clays that have many cations in the nonpolar and hydrophobic PP, amino-silane was introduced to modify the surface of the clays. Also, to improve the compatibility of the modified nanoclay with PP, a PP-graft-maleic anhydride was used as a compatibilizer. From Fourier transform infrared spectroscopy analysis and the mechanical property test results, it was confirmed that the surface of the nanoclay was properly modified, and it was successfully dispersed in the PP matrix. The composite was investigated by electron microscopy to analyze its morphology and the degree of dispersion of the nanoclay. An analysis of oxygen permeability according to nanoclay content was performed, and it was found that the higher nanoclay content makes the decrease in oxygen permeability. In addition, a shelf-life test was carried out to determine the relationship between decreased oxygen permeability and food preservation performance. The preservation performance of the food package prepared with the resin made in this study was improved because of the improvement in mechanical properties and oxygen barrier property.