In this study, the use of less hygroscopic plasticizers has been
envisaged as a way of modifying bioplastic release/swelling properties.
In the first part of this study, bioplastics formulated with
polyethylene glycol (PEG), water and wheat gluten were manufactured,
in order to determine the effect of varying PEG molecular
weight. Afterwards, the addition of different types of modifying
agents, on a specific formulation, was assessed to enhance the
bioplastic controlled release of an “active agent”, KCl (a source
of essential micronutrients for agriculture). Dynamic mechanical
thermal analysis (DMTA), differential scanning calorimetry (DSC),
release and water absorption tests were carried out in order to
study the influence of these variables.