High Strength, High Barrier Polymeric Packaging Film Based on Multilayered Structure

ABSTRACT Polyolefins have attracted considerable attention as packaging materials because of their outstanding light weight, flexibility, strength, transparency, and facile processability. However, because of their high permeability, polyolefins were usually used with high barrier material (i.e., ethylene vinyl alcohol (EVOH), nylon, polyvinylidene dichloride) for packaging applications, resulting limited recycling of packaging films. Herein, we manufacture high strength, high barrier linear low‐density polyethylene (LLDPE) films with a limited amount of EVOH using co‐extruder with layer multiplier. To achieve high barrier and high strength property, structures of films were carefully designed to have 1, 2, 4, 8 layers of EVOH while maintaining the overall thickness of EVOH and LLDPE. The oxygen permeability of multilayer films was significantly decreased from 0.1 to 0.01 cc/m 2 ·day·atm when the films have eight layers of EVOH. In addition, the mechanical properties of multilayer films, such as elongation and toughness, were improved as decrease the thickness of each EVOH layer. In addition, molecular dynamics (MD) simulation was conducted to confirm that O 2 was stagnant between the LLDPE and EVOH interfaces.