These results indicate that by a judicious choice of the
organoclay fillers, it is possible to tune the biodegradable
properties of the bio-nanocomposite materials. However,
the thermal stability of the organic part, such as quaternary
ammonium salts which is used up to 40% for surface modification
of nanoclay, of the organoclay needs to be considered
before drawing conclusion. At temperatures of commercial
scale processing using extrusion or injection molding
required for most polymers, the thermal stability of the
ammonium salts is very limited as most of the structures
tend to Hofmann elimination resulting in volatile olefins
and amines [107]. The thermal degradation of ammonium
salts starts as low as 180 ◦C and is furthermore reduced by
catalytically active sites on the aluminosilicate layer.
Though the possible enhancement and controlled
biodegradation of bio-nanocomposites are yet to be
studied [102,109,110], the biodegradability property of
bio-nanocomposites can be properly used for the development
of biodegradable nanocomposite packaging materials
with controlled biodegradation function. However, the
proper stability and durability of the bio-nanocomposite
packaging materials should be maintained during their
useful shelf-life to perform their packaging functions.
It is of interest to recognize that the nanoparticles
have two opposite effects on polymer nanocomposites,
i.e., degradation and stabilization depending on
processing and environmental conditions [110]. Hybrid
bio-nanocomposites, such as layered silicates embedded
in a polymeric matrix, improve stability and their
biodegradability can be fine tuned by varying the amount
of solvents used or by the incorporation of different types
of organocays modified surface with different types of surfactants.
Such innovative properties of nanoparticles can
be exploited in the packaging industry depending on the
final use.
5. Antimicrobial properties