In order to make PLA matrix less susceptible to the catalytic
action of ZnO nanoparticles during the melt blending
process and subsequent film processing, the nanofiller surface
treatment with silane agents was considered as a prerequisite,
leading to significant enhancements of both
thermo-mechanical and molecular properties with respect
to the use of untreated ZnO [33]. In relation to the transport
properties of PLA films, it is noteworthy to mention
that according to Tsuji et al. [36], the changes in Mn of PLLA
films in the range of 9 104–5 105 g mol1and D-lactide
unit content up to 50%, lead to insignificant effects on the
water vapor transmission rate (WVTR). In contrast, the
WVTR of PLA films were found to decrease monotonically
with increasing the degree of crystallinity from 0% to
20%, while levelling off for values exceeding 30%.