Permeation characterization and modelling of polyethylene/clay nanocomposites for packaging

The approach of upgrading barrier properties of polymer with nanofillers is effectual and well established now-a-days to manufacture films and quality packaging. This research deals with enhancement of barrier attributes of clay-based high density polyethylene nanocomposites against oxygen and water permeability. Na-Montmorillonite and two grades of kaolin clays were used for HDPE/clay nanocomposites preparation in twin-screw extruder with temperature profile of 160, 170, 180, 190 and 200 °C along the extruder at 110 rpm with clay loading up to 10 wt%. The extent of maximum reduction in water and oxygen vapors permeation was more prominent at 5 wt% sample of each clay. XRD analysis revealed no exfoliation in kaolin clay samples but indicated presence of exfoliation in Na-MMT samples. SEM and TEM micrographs revealed nano-level dispersion for both kaolin clays and Na-MMT and agglomerate formation at high wt% of clays. Experimental data for oxygen and water vapors permeation through nanocomposites were fitted on Nielsen, Cussler and Gusev–Lutsi models. Modelling of barrier performance was utilized for acquiring aspect ratio of filler for nanocomposites. Maximum and average aspect ratio of fillers and third-degree polynomial equation for nanocomposite, through curve fitting, were determined to predict improved barrier properties of nanocomposites.