Mechanical Recycling of Multilayer Flexible Packaging Employing Maleic Anhydride as Compatibilizer

Mechanical recycling is an important alternative to reduce the amount of fossil resources needed to produce plastic materials. This research evaluated the theoretical recyclability of two multilayer films for meat products packages, composed of PE/PE/ad/PA/ad/PE/PE (Film A) and PE/ad/PA/EVOH/PA/ad/PE (Film B), using the RecyClass tool. Then, an extrusion was carried out as a post-industrial recycling step. Recycled films were prepared without compatibilizer and with different concentrations (5-7%) of a commercial compatibilizer based on maleic anhydride (MA), and were evaluated according to their chemical, thermal, morphological, and mechanical properties. Films without compatibilizer were classified as non-recyclable using RecyClass. However, the use of a compatibilizer proved to be promising for the recycling of these packages. The infrared spectra showed that the PA-MA-PE copolymer was obtained during the mixing, confirmed by the microscopy images, where the compatibilizer provided an adhesion between the mixing interfaces. The melting temperature of PE proved to be stable during processing. However, the compatibilizer addition resulted in changes in the PA melting temperature in Film A. Films with compatibilizer showed a significant increase in elongation at break compared to films without it. These results confirm the strong efficiency of PA-MA-PE compatibilization, which is an alternative for recycling multilayer packaging of meat products.