Effect of gamma irradiation on thermophysical properties of plasticized starch and starch surfactant films
In this work the influence of gamma irradiation on the thermomechanical properties of the films formed
in potato starch–glycerol and potato starch–glycerol–surfactant systems were examined by Dynamic
Mechanical Analysis, DMA, and Differential Scanning Calorimetry, DSC, and the results were correlated to
the amount of the volatile fraction in the films.
The starch was irradiated with a dose of 30 kGy. The films were prepared by casting from solutions
with addition of 0, 20 and 30 wt% of glycerol. Two endotherms attributed to glass transitions were
observed in water or glycerol plasticised samples, the first one shifting to higher temperature after
irradiation. A similar shift was observed after irradiation of films prepared from starch–sodium laurate
and starch–sodium palmitate systems, while a decrease in glass transition temperature was observed in
the case of starch–cetyltrimethylammonium bromide films. Small differences in the content of the
volatile fraction reached after the appropriate conditioning had no impact on the direction of
temperature shift of Tg observed after irradiation.