Polyhydroxyalkanoates-Based Nanocomposites: An Efficient and Promising Way of Finely Controlling Functional Material Properties

Abstract

This chapter aims at highlighting on recent advances in preparation, characterization, and functional properties of polyhydroxyalkanoates (PHA) and their layered silicate nanocomposites. These materials have attracted considerable interest in material science research. PHA are microbial polyesters produced by numerous bacteria in nature as intracellular reserve of carbon or energy. They are also generally biodegradable, with good biocompatibility, making them attractive as biomaterials. Nevertheless, biodegradable polymers alone as PHA have limited physical and mechanical properties which, at present, do not allow them to fully replace the mainstream plastics. The preparation of bionanocomposites defined as a combination between PHA and inorganic nanofillers as layered silicates is a route to enhance some of the biodegradable PHA properties. Preparative techniques include essentially intercalation of PHA in solution and melt intercalation.

This critical review highlights the major developments in this area during the last decade and focuses on the control of the functional PHA properties using layered silicate as mechanical behavior, thermal stability, gas barrier properties, and biodegradability. This review also points out some contradictory trends, which result from combined and antagonist effects. This proves that the PHA-based nanocomposite morphologies should be comprehensively investigated for predicting and interpreting the complex phenomena which can take place in such systems.