Cellulose nanocrystals and related polymer nanocomposites

Abstract

Fossil energy depletion and growing environmental concerns have brought up increasing interest in bio-based eco-efficient and high technology materials. This particular situation provides unique bionanocomposites possessing outstanding properties, which have been never found in conventional composites. It is possible to obtain nanoelements from different renewable resources depending on their biological origin, e.g., cellulose, starch, chitin. Among them, main research is dedicated to cellulose whiskers as it is the most abundant in earth, and also due to their low cost, renewability, biodegradability, strength, light weight, nanoscale dimension and unique morphology. The designation ?whiskers? is used to designate elongated crystalline rod-like nanoparticles. This chapter mainly focuses on the preparation, morphological features and properties (mechanical, thermal and barrier) of biodegradable bio-based nanocomposites, being cellulose the nano-sized reinforcement. Drastically enhanced mechanical properties are obtained, well understood by virtue of the formation of a continuous network of whiskers. Aspect ratio of cellulose whiskers is also an important property in enhancing the tensile strength of nanocomposites. Impressive mechanical properties make them ideal candidates for the processing of composites. Nanoparticles extraction sources and methods, are also discussed in detail, as well as the processing techniques of the final nanomaterials.