The abrupt change in elongation at break showed by PLAe15 wt
% OLA after only 3 days of storage (Fig. 4) could be explained by the
reduction in PLA chains mobility at the testing temperature,
changing the mechanical behaviour of the material from ductile to
brittle. It is known that the mechanical properties of polymers
depend on the Tg of the material and the temperature at which
properties are determined, existing a limit difference between
them caused by a drastic change in the elongation of the material.
Baiardo et al. [8] observed that PLA plasticized with PEG of different
molar masses between 400 Da and 10 kDa suffered a large change
in mechanical properties when Tg of the corresponding blend was
around 35 C, regardless of the plasticizer. The change in elongation
at break was in all cases of two orders of magnitude while the