Our challenge has been to produce starch-based films that can
be used in applications such as the production of sustainable
biodegradable packaging materials. As a consequence of previously
reported research, thermal reactive extrusion was chosen in this
study to improve starch film properties. It was hypothesized that
starch, glycerol and alcohols (MetOH and EtOH) will intimately
react in one-step (oxidation/etherification or esterification) when
processed at the temperatures, pressures and shearing rates present
inside a twin-screw extruder. This study involved the use of
methanol and ethanol and their mixtures that required special air
ventilation of the laboratory to avoid any safety hazards. The
properties of the films were examined by gravimetry, X-ray powder
diffraction (XRD), thermogravimetric analysis (TGA), tensile testing
and dynamic mechanical thermal analysis (DMTA). The microscopic
structures of the films were examined by Fourier Transform
Infra-red (FTIR) and proton nuclear magnetic resonance spectroscopy
(1HNMR) to provide further evidence on the differences in the
mechanical properties.