The different active PLA:GSPLA films were obtained by melt
blending in a twin-screw extruder (DSE 20-40D, Brabender, Germany).
Temperature was set at 200e205 C and the screw speed
was 70 min1
. Proallium® was introduced in the mixer once the
polymer was already in the melt state. Different concentrations (2%,
5% and 6.5% w/w) of Proallium® were fed into the barrel through
the lateral liquid port at L/D 10 to reduce possible volatility and
degradation losses. In the control films, Proallium® was not added.
The average width and thickness of the films were approximately
10 cm and 80 mm, respectively. All developed films were storedat 20 C and darkness before their characterisation.