Biodegradable Composites Based on Thermoplastic Starch and Talc Nanoparticles

Abstract

Nowadays, technological interest is focused on a new generation of composite polymers based on biodegradable matrices from renewable raw materials with either organic or mineral fillers. These biocomposites have several advantages mainly due to their eco-friendly nature since they can be naturally degraded plus their renewable origin. Among other biopolymers, starch is a good candidate because of its availability, biodegradability, and low cost. Naturally, starch is not considered as a thermoplastic polymer, but its processing with plasticizers, under high temperature and shear stresses, allows the disruption of its granular structure, becoming into thermoplastic starch (TPS). Main disadvantages of TPS materials are related to their poor mechanical properties and moisture absorption. Addition of either natural fillers or mineral particles to improve their final properties is an interesting alternative. In this sense, talc particles can be used to reinforce starch matrices mainly due to their laminar morphology and nanometric thickness. The aim of this chapter comprises the development of starch-based composites with talc nanoparticles. Well-dispersed and well-distributed nanoparticles in TPS matrix are obtained by direct melt mixing, and thus, nanocomposite TPS film properties were improved. These results are interpreted in terms of an accurate analysis of the processing– properties–structure relationship.