3.6. Thermal analysis
Differential scanning calorimetry was performed with a Shimadzu TA-50WSI calorimeter calibrated
with indium and zinc. The search for a clear-cut glass transition temperature feature in the DSC tracings
was fruitless for A4B1 and A4B3 treatment. In addition the melting point (Tm) of A1B1 and A4B1 was
also not detected. Determination of glass transition temperatures of thermoplastic starch by DSC is a hard
task, as a result of the fact that the starch is made up of two polysaccharides: amylose and amylopectin.
Depending on the starch composition, DSC thermograms can show higher or lower Tg values, or both at
the same time. The higher and lower phases were detected in most cases in blends containing less than
30% glycerol [37].