Synergistic Effect of Cellulose Nanofiber and Nanoclay as Distributed Phase in a Polypropylene Based Nanocomposite System

Since the plastic-based multilayer films applied to food packaging are not recyclable, it is necessary to develop easily recyclable single materials. Herein, polypropylene (PP)-based cellulose nanofiber (CNF)/nanoclay nanocomposites were prepared by melt-mixing using a fixed CNF content of 1 wt %, while the nanoclay content varied from 1 to 5 wt %. The optimum nanoclay content in the PP matrix was found to be 3 wt % (PCN3), while they exhibited synergistic effects as a nucleating agent. PCN3 exhibited the best mechanical properties, and the tensile and flexural moduli were improved by 51% and 26%, respectively, compared to PP. In addition, the oxygen permeability was reduced by 28%, while maintaining the excellent water vapor permeability of PP. The improvement in the mechanical and barrier properties of PP through the production of PP/CNF/nanoclay hybrid nanocomposites suggested their possible application in the field of food packaging.