FIGURE 7.

Sacrificial molecules increase the stiffness and the toughness of a material. The initial slope of the pulling curve is a measure for the stiffness of a material. In the case with sacrificial molecules (upper curve) this slope is steeper (dash-dotted line) than the slope (dotted line) in the case without sacrificial molecules (lower curve). The extra energy that is dissipated through the sacrificial molecules (shaded area in the curve) is a measure for the increase in toughness of the material.