shows the tension–deformation curves for both the puresoy-protein
and the nanocomposite films. The former film, the
control, exhibited moderate properties: tensile strength up to
about 3 MPa, elongation at break of about a 38%, and a Young's
modulus of about 1.2 MPa; values that are found within the same
range for other protein films in the literature [51,52,54,57–61].
With the addition of increasing amounts of clay a progressive
enhancement in the resistance to breakage and in the modulus of
elasticity was acquired along with a substantial decrease in the
extent of elongation of the films relative to that of the control with
pure protein—e.g., at 10 g of MMT per 100 g SPI, the values