Robust Tear-Resistant Blown Nanocomposite Films for Barrier Packaging: Role of Clay Platelet Thickness in Tear Mechanics and Barrier Performances

Abstract

A linear low-density polyethylene (LLDPE) nanocomposite film with organically modified clay (Cloisite 30B) as a filler and LLDPE-grafted-maleic anhydride as a modifier was prepared by extrusion film blowing. The thermal properties, as investigated by thermogravimetric analysis and differential scanning calorimetry, indicated increased crystallinity with enhanced thermal stability. Morphological attributes of nanocomposite films were demonstrated by transmission electron microscopy, and the thickness distribution of clay platelets was analyzed by kite plot. The radius of gyration (R g) of LLDPE chains is studied by small-angle X-ray scattering from the Guinier region. The analysis of tear fracture and its associated surface morphology was done by scanning electron microscopy. The oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) were measured for nanocomposite films. The 5 wt % clay-loaded nanocomposite film showed a ∼23.5 and ∼33.4% decrease in WVTR and OTR, respectively, compared to that of neat LLDPE films. The effect of crystallinity on tear energy and the influence of clay thickness in film transmittance on the barrier properties of various nanocomposite films with varied clay content were discussed. The paper demonstrated the correspondence between lower R g values and low platelet thickness, which in turn remained directly correlated to OTR and WVTR.

Electrospun Nanofibrous Mat-on-Film Bilayered Halochromic Freshness Marker-Enabled Intelligent Food Packaging Film Based on Red Cabbage Anthocyanins

“…Furthermore, the oxygen plasma treatment has caused an increase in the OTR and WVP values, an observation attributed to the presence of the oxygen-rich functional moieties, as evident from the functionality verified by the XPS-specific peaks, which facilitates the diffusion of the water and oxygen molecules. However, the treated clay-dispersed LL films (LL CP ) showed better barrier performance than the neat untreated LL due to the intercalated structure of clay in the polymer matrix …”