(Fig. 6) demonstrates both the morphology at macroscopic and microscopic levels of the plastic zone of a PLA/EVA50 blend after fast deformation. In the PLA/ EVA50 blends, the interfacial adhesion between the PLA and the EVA50 is relatively strong due to a good compatibility, while the EVA50 is a non-crosslinked rubber with a low modulus (E0 2 MPa at ambient temperature as measured by DMTA) but without chemical crosslink. Consequently, the surface energy per unit area for the EVA50 to generate new surfaces associated with cavitation is low. This is beneficial for rubber cavitation with stress, because cavitation will only be initiated if the energy gained by relieving the stress (Ustrain) is greater than the energy needed to create a new surface (Usurface) [37].