A one-step thermal extrusion process has been investigated for the modification of starch with alcohol in
order to improve the film properties. Unmodified starch/glycerol mixtures containing Methanol
(MetOH), ethanol (EtOH) and their combinations (5, 10 and 15 wt%) were thermally extruded to produce
thermoplastic. The final hot-pressed film showed increased stiffness and crystallinity, while having
decreased moisture uptake due to oxidation and alcohol complexing molecular interactions. The Young's
Modulus, tensile strength and elongation at break increased by 60%, 15% and 32% respectively, for 5 wt%
MetOH derived film, compared to the control. The film moisture content was reduced by up to 15 wt% for
5 wt% EtOH-derived film. Generally the crystallinity increased in the alcohol-derived films due to an
increased complexing of alcohol with starch forming the VH polymorph. Fourier transform infra-red
(FTIR) and proton nuclear magnetic resonance (1HNMR) spectroscopic analysis were used to discuss
the molecular interactions between the starch and alcohol molecules.