[nanoPost] Nano-Hybrids in food packaging

Research Centre Greece

The area of polymer/layered silicate nanocomposites has been of special interest. In these systems three different types of structure can be observed: the phase separated structure, where the polymer and the inorganic material are highly immiscible, the intercalated structure, where the polymeric chains reside between the layers of the silicate, and the exfoliated structure, where the platelets are well dispersed in the polymeric matrix. A central objective of the group’s involvement is the understanding of the interactions between the polymer chains and the surfaces of the inorganic material in order to be able to control the miscibility and thus the structure of the hybrid material by modifying the interactions.

The control of the structure in each case is correlated with the final properties, which is the main interest of the end user. This optimization of the structure and the properties is especially important in the case of widely-utilized commodity polymers like polyethylene or polypropylene, which, however, are not particularly miscible with the layered silicates due to their non-polar character.

Polyethylene is used in films for food packaging or agricultural applications and it is clear that products with lower permeability in gases and better mechanical and surface properties are important. One of the major applications of polypropylene is in the car industry, where it is very important that the final product possesses both stiffness and toughness, is easily processable and shows high scratch and flame resistance. It has been anticipated that optimized polymer/layered silicates hybrids can significantly improve these properties.

The understanding of the interactions between the polymer and the surfaces as well as of the mechanism of intercalation can also provide the opportunity to develop responsive systems by appropriately tuning these interactions.