Nano-biocomposites: Biodegradable polyester/nanoclay systems

In the recent years, bio-based products have raised great interest since sustainable development policies tend to expand with the decreasing reserve of fossil fuel and the growing concern for the environment. Consequently, biopolymers, i.e., biodegradable polymers, have been the topic of many researches. They can be mainly classified as agro-polymers (starch, protein, etc.) and biodegradable polyesters (polyhydroxyalkanoates, poly(lactic acid), etc.). These latter, also called biopolyesters, can be synthesized from fossil resources but main productions are obtained from renewable resources. Unfortunately for certain applications, biopolyesters cannot be fully competitive with conventional thermoplastics since some of their properties are too weak. Therefore, to extend their applications, these biopolymers have been formulated and associated with nano-sized fillers, which could bring a large range of improved properties (stiffness, permeability, crystallinity, thermal stability). The resulting 'nano-biocomposites' have been the subject of many recent publications. This review is dedicated to this novel class of materials based on clays, which are nowadays the main nanofillers used in nanocomposites systems. This review highlights the main researches and developments in biopolyester/nanoclay systems during the last decade.