Improvement Approach for Gas Barrier Behavior of Polymer/Clay Nanocomposite Films

Abstract

Polymer nanocomposites (PNC) include a copolymer or polymer which has nanoparticles dispersed in the polymer matrix at the nano-level. One of the most common types of polymer nanocomposites contain smectic clays as the nanoparticles. These clay minerals increase the mechanical properties of standard polymers and improve barrier properties. For optimum barrier properties, Layer-by-Layer assembly (LbL) is one of the most effective methods for depositing thin films. LbL methods however, are quite tedious and produce large quantities of waste. A newly discovered phenomenon of self-assembled polymer nanocomposites utilizes entropic forces to drive the assembly to spontaneously form a larger nanostructured film. This approach allows polymers and nanoparticles with high particle loadings to be mixed, and create the super gas barrier films. We have developed a coating technique which can be employed to make self-assembled gas barrier films via inkjet printing. This technique is industrially scalable and efficient. This is because it does not need any rinsing step and drying steps as required in LbL. The influence of different polymers Polyvinylpyrrolidone (PVP) and Poly (acrylic acid) PAA with Montmorillonite (MMT) nanoclay solutions on Polyethylene terephthalate (PET) substrate is examined to study their effectiveness as a gas barrier film. The results showing the excellent oxygen barrier behavior of a combination of PVP and MMT Nano clay nanocomposite with high transparency. These high barrier gas nanocomposite films are good candidates for a variety of food packaging applications.