Abstract
In this work, thin transparent breathable films were prepared for food packaging applications. The films were obtained by the solvent casting method from both the binary blends Pebax(®) MH1657 copolymer/ hydroxyl-terminated polyethylene glycol (PEG(OH)) and Pebax(®) MH1657/polyethylene glycol dimethyl ether (PEG(DME)) as well as the ternary blend Pebax(®) MH1657/PEG(OH)/PEG(DME) with a 50/50 and 37.5/62.5 PEG(OH)/PEG(DME) weight ratio for additive amounts comprised between 0 and 50 wt.%. The microstructure of these materials was investigated by differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS) analyses. Regardless of the PEG's nature, for a PEG amount inferior to 30 wt.%, the Pebax(®) and PEG phases were totally miscible. For higher amounts, a phase separation was obtained. In the presence of PEG, a decrease in crystallinity was obtained. The effects of the nature and amount of PEG on the thermo-mechanical, hydration, and gas (CO(2), O(2)) transport properties were investigated. A study of the film's stability in terms of composition over time was also performed. From this work, a wide range of films could be proposed with a stable composition over time and adjustable mechanical and gas transport properties for the prolongation of the shelf-life of highly breathable fresh products.