2.5. Mechanical properties
A Testometric Machine M350-10CT (Testometric Co. Ltd., England) was used to study the mechanical properties
of the film specimens in general accordance with ISO 527-3. The initial grip separationwas set at 50mmand cross-head
speed at 50 mm/min. Tensile strength (TS) was calculated by dividing the maximum load on the film before failure by
the cross-sectional area of the initial specimen. Elastic modulus (EM) was determined according to the slope of
the stress/strain curve in the linear range. Elongation at break (E) was defined as the percentage change in the
length of the specimen compared to the original length between the grips. At least five replicates for each type of
film were tested.