parts of various plants, starch has been of great interest in recent years
because of its environmental friendliness. Starch is such a polymer which is
constituted by the linkage of amylose (20-30%) and amylopectin (70-80%)
with various percentages, depending on the type. Starch macromolecules
has the consistency of hydrogen bonds which induces the diminishments in
the mobility of these molecules, consequently native starch becomes hard to
be processed. To manufacture higher qualified productions, cellulose plays
an important role in terms of dealing with the problem pertaining to hardness
in processing. Cellulose is also another raw material which is linear polymer
of anhydroglucose being the most common substance on the planet; moreover,
since it is highly economical, reasonably priced and ecologically friendly,
cellulose is broadly applied in packaging industry, as well. Nevertheless, some
evident drawbacks of starch and cellulose mixture to exist drives new
wayouts to be explored, which concludes the addition of plasticizers, namely
polyols (especially, sorbitol, glycerol and ethylene glycol) and
monosaccharides (mannose, glucose, fructose) (Farahnaky A. et al 2012).
The primary functions of the additives are to change the ability to absorb
moisture content, to increase the flexibility level of films, to decrease
intermolecular interactions of chains. Additionally, when starch films are dried
in ambient environments without plasticizers, they collapse into pieces. In
both monosaccharides and polyols, the main components that affect the
change in the properties of raw materials are hydroxyl groups. To be more
elaborated, these hydroxyl groups are interracted with the hydrogens of raw
materials. In addition, starch and cellulose granules experience gelanization
process, and during this procedure, amylose and amylopectin molecules are
released into solution which results in the higher flexibility quality of the
production. This operation leads the developments in the properties, such as