There are environmental concerns by the general public to reduce the carbon footprint and issues surrounding the disposal of fossil-based non-degradable plastics that pollute the environment. The current and continuing trend towards environmental sustain-ability along with increasingly stringent governmental legislation is driving manufacturers to increase investment and development in biodegradable plastics. Total consumption of biodegradable polymers is also expected to grow by nearly 15% annually form 2012 to 2017 in Asia, Europe and North America. Increasing prices and limited application of biodegradable plastics have led many researchers to focus on production of starch-based polymers to replace fossil-based plastic.
Thermal extrusion is one of the most widely used techniques to process starch-based polymers. It allows easier handling in the presence of small quantities of solvent, has a broad range of processing conditions and ensures good mixing that minimises phase separation. Starch can be processed into thermoplastic materials in the presence of plasticizers using heat and shear by extrusion.