Morphology of LDPE-EVA blended films mixed in twin-screw extruder showed that the two compositions in
blended films are discrete and immiscible. Moreover, the SEM micrographs showed better distribution of EVA
phase in matrix when the composition of EVA was no more than 10%wt. From the DSC results, it confirmed that
the two-polymer blended film were immiscible.
The study of morphology of the films incorporated with EOs reveals rough and grainy surface because of
discontinuous phase of polymer and evaporation of EOs. Residual concentration of EOs showed that different EOs
could demonstrate different rate of volatilization. Solubility parameter is the main factor to be taken into
consideration in term of residual concentration after processing. For the CB, its residual concentration is even
noticeable due to its polarity different to the polymer backbone.
In term of antimicrobial activity testing, the film incorporated with CB showed the best performance of inhibiting
the growth of E. coli and S. aureus regardless of its low retention. Nonetheless, the relatively higher retention of
EOs in the film with SB is incapable of resisting both microorganisms. Lastly, the modification of film with any
EOs illustrated a well-maintained condition for tomatoes comparing to the ones packed in the film with no EOs even
a long period of two months. Consequently, LDPE-EVA films incorporated with such EOs are practically suitable to
use for food and agricultural product packaging