Barrier properties biodegradable polymer/layered silicate

The main limitations of these biodegradable polymers towards their wider application are their relatively low thermal and mechanical resistance and limited gas barrier properties, which limit their access to certain industrial sectors, such as food packaging, in which their use would be justified when biodegradability is required. Nevertheless, the above drawbacks could be overcome by enhancing their properties through the use of filler and/or additives. In the last two decades, the addition of nanofillers to polymers has attracted great attention for the potentiality of these materials to improve a high number of polymer properties for example, polymer layered silicate nanocomposites, because of the nanometer size of the silicate sheets, exhibit, even at low filler content (1-5 wt%), markedly improved mechanical, thermal, barrier and flame retardant properties, in comparison to the unfilled matrix and to the more conventional microcomposites. ... 

Biodegradation of PCL-based nanoeomposites has been scarcely studied until now. Tetto et al reported that organically modified layered silicates accelerate PCL biodegradation. Contrarily, Maiti et al reported that the biodegradation of PCL-based nanoeomposites can be depressed by the presence of nanoparticles, probably due to an improvement of the barrier properties of the polymer matrix. 

This book covers both fundamental and applied research associated with polymer-based nanocomposites, and presents possible directions for further development of high performanee nanocomposites. It has two main parts. Part I has 12 chapters which are entirely dedicated to those polymer nanocomposites containing layered silicates (clay) as an additive. Many thermoplastics, thermosets, and elastomers are included, such as polyamide (Chapter 1), polypropylene (Chapter 4), polystyrene (Chapter 5), poly(butylene terephthalate) (Chapter 9), poly(ethyl acrylate) (Chapter 6), epoxy resin (Chapter 2), biodegradable polymers (Chapter 3), water soluble polymers (Chapter 8), acrylate photopolymers (Chapter 7) and rubbers (Chapter 12). In addition to synthesis and structural characterisation of polymer/clay nanocomposites, their unique physical properties like flame retardancy (Chapter 10) and gas/liquid barrier (Chapter 11) properties are also discussed. Furthermore, the crystallisation behaviour of polymer/clay nanocomposites and the significance of chemical compatibility between a polymer and clay in affecting clay dispersion are also considered. 

---