Polymer Nanocomposites are a new class of materials with much superior properties such as mechanical, thermal, flame ratardancy, gas barrier etc. They are mixtures of a polymer matrix and reinforcing filler that have at least one dimension in nanometer range. The uniform dispersion of 2D- layered nanofillers such as layered organosilicates, graphene etc results in a very large surface area and a network of platelets able to produce a tortuous path which works as a barrier structure to retard the permeation of gases , water vapour etc. A high tortuosity leads to higher barrier properties and lowered permeability in polymer nanocomposites. The barrier properties of polymers are generally poor when compared to metals and glass because of low density and open structure through which small molecules such as gases can easily pass through, thus presenting a limitation in many applications.
The enhancement of barrier properties of polymers is therefore very important in areas such as packaging, protective coatings, inflatable products and in construction materials. Various polymeric films, like TPU, PP, PE, PET etc including many others are being used for packaging and protective coating applications where the enhancement of gas barrier properties remains one of the most important parameters. In this research project the aim is to develop advanced polymer nanocomposite based films and coatings with improved gas barrier property to gases such as helium, nitrogen, oxygen, water vapour etc ; apart from having desired mechanical strength, flexibility at a range of service temperatures, weather resistance, thermal stability etc. for advanced applications such as inflatable products and packaging. The nanofillers such as clays, graphene, graphene oxide, nanocellulose (CNC and CNF) and other layered metal salts will be explored. Thermoplastic polyurethane would be the matrix for inflatable product applications and biodegradable polymers like PLA would be the choice for packaging materials. The emphasis would be on advancing fundamental insight in order to achieve competitive improvements in nanocomposite barrier, weather resistance and mechanical performance. The challenges like nanomaterial pre-treatment and scalable processing to get immaculate nanofiller distribution and dispersion resulting in a fully-exfoliated morphology of layered nanofillers will be extensively investigated. The outcome of this project will significantly impact the new high performance material development having applications in the areas like inflatable on one hand and eco-friendly packaging on the other.
The project aims to develop polymer nanocomposites based films, coatings and laminates for advanced gas barrier applications. The focus would be on following two areas:
- Thermoplastic Polyurethane (TPU) based nanocomposite films and coatings for inflatable products.
- Biodegradable Food packaging films with improved gas barrier and antimicrobial properties.