CHAPTER 7. Starch Nanocomposites

Abstract

In recent times, renewable resource-based biopolymers like carbohydrates, lignin, chitosan, vegetable oils, etc., are being investigated by material scientists as environmentally friendly alternatives to traditional oil-derived plastics. However, these natural polymers do not demonstrate the same material properties as the traditional plastics, which limits their application potential. Starch is an environmentally friendly, abundantly available, low cost biopolymer. In spite of its low cost and renewability, it has a few major drawbacks like high moisture absorption, poor processability and low mechanical properties. Starch is, therefore, commonly converted into a usable product by blending it with other polymers or by combining it with reinforcing fillers to produce a starch composite. Starch nanocomposites are now an important area of green materials research. Starch can be used as a matrix polymer or as a reinforcing filler in a starch nanocomposite. Starch is first converted into thermoplastic starch to improve its processing behavior, and different nanofillers are then incorporated into it, resulting in enhanced mechanical properties, higher thermal stability, improved barrier property, etc. In another approach, starch is converted into starch nanoparticles and the latter are then incorporated into various matrices to prepare starch nanocomposites. This chapter reports on the material properties of such starch nanocomposites, their fabrication methods, advantages and drawbacks, application potentials, etc. Starch nanocomposites are envisaged in the future development of biomimetic materials to provide novel bionanocomposites as multicomponent and multifunctional materials. Starch-based nanocomposite research is a novel interdisciplinary field that includes the development of bio-nanomaterials emerging from the interaction of biotechnology, materials science and nanotechnology. In the last few years, the investigation of such materials has received attention from researchers with expertise in diverse areas. In this chapter, the recent trends in developing starch nanocomposites are summarized, while also providing insights into future trends.