Development of Breathable Pebax^®/PEG Films for Optimization of the Shelf-Life of Fresh Agri-Food Products

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 (PEGOH) and Pebax® MH1657/polyethylene glycol dimethyl ether (PEGDME) as well as the ternary blend Pebax® MH1657/PEGOH/PEGDME with a 50/50 and 37.5/62.5 PEGOH/PEGDME 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 (CO2, O2) 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.

Keywords

• breathable film
• CO₂/O₂ ideal selectivity
• stability
• microstructure
• hydration properties
• thermo-mechanical properties