Multilayer structures based on annealed electrospun biopolymer coatings of interest in water and aroma barrier fiber-based food packaging applications

In this research work, for the first time, a fiber-based packaging material was coated by annealed electrospun ultrathin fibers of poly(3-hydroxybutyrate), poly(vinyl alcohol), and polylactide. The resultant mono- and multilayer structures self-adhered to the paper substrate and were characterized in terms of morphology, optical, and barrier properties. Additionally, the use of a static flat plate and rotating mandrel collector as well as the application of different electrospinning deposition times were analyzed. The thermally treated electrospun biopolymers yielded totally transparent films while, due to the opaque nature of the uncoated paper substrate, the developed packaging materials were also opaque but with a glossier surface finish provided by the bioplastic coating. The annealed films obtained from random electrospun fibers, that is, the mats of ultrathin fibers collected on the static plate, presented higher transparency and thickness and also enhanced barrier performance. On the overall, the developed annealed electrospun biopolymer coatings resulted in a significant improvement of the paper barrier properties to water and limonene vapors, being the paper/poly(vinyl alcohol)/poly(3-hydroxybutyrate) film the best performing multilayer packaging structure