Abstract:

Novel composites based on engineered clays and different types of commercial thermoplastics, which exhibit enhanced properties referred to the polymer base materials, are presented. Simultaneous effects on enhanced properties occur and affect gas barrier, water permeability and absorption, UV light blockage, mechanical and thermal behavior. These composites could have additional capacities such as antioxidant and antimicrobial activity when appropriate modifications are made on the clay surfaces.

Additionally, results describing the active performance of clay-based composites in terms of oxygen scavenging are presented. In order to demonstrate the efficiency of these novel technologies, oxygen scavengers based on engineered iron-based clay and biocompatible catalyst clays were incorporated into polyolefin and PET, resulting in materials with high oxygen absorption capacity.

Despite the presence of mineral particles in a transparent polymer matrix, these did not affect significantly the optical properties of the composite. The iron-based clays are an exception since the presence of the zero-valent iron conferred a black background that in low dossing levels could be seen as fly wing effect (a grey semi-transparent layer).

The presented passive and active systems are innovative proposals that can be tailor-made to preserve and extend the shelf-life of packaged food and to improve the properties of plastic products used for that purpose.