The possibility of plasticizing starch by ionic liquids was
shown in our recent study [19]. This current study discusses
the effects of the different operating conditions of
carbon dioxide (CO2) on the plasticization of starch by
ionic liquid. Glycerol was used as a model plasticizing
agent in order to establish a comparison with BMIMCl.
First, we evaluated the structural and thermal properties
of starch treated with plasticizer under supercritical
CO2 directly into the high pressure vessel.
The same approach was adapted to the starch plasticized
by the ionic liquid through the extrusion step and
heat-pressed into disk plates. The samples underwent different
treatments of CO2 pressure, temperature and the
duration of processing time in order to study their influences
on the properties of the plasticized starch. In all
cases, the supercritical treatments not induce any changes
in the visual morphology structure of TPS (no foaming phenomena
occur).