Conclusions
New nanocomposites based on PLLA, GO and organomodified
GO were prepared. The crystallization and biodegradation rates of
the PLLA nanocomposites increased with increasing the
filler
content. To achieve improved properties in the nanocomposites
formation of an interface between the polymer matrix and the
nanofiller is needed. The amorphous phase showed no substantial
change in Tg, however the heat capacity jump at the glass transition
decreased in the nanocomposites, suggesting that a fraction of
polymer is immobilized. This result provides an explanation for the
observed improvement of the mechanical properties of the
nanocomposites. The improvement is maximal for 1 wt%
filler,
in good correlation with reduction of the heat capacity jump at Tg,
and of the dielectric strength of the corresponding segmental
relaxation. Compared to effects of
filler content, effects of organic
modification of the
filler used are moderate.