Experimental and numerical study on transient elongational viscosity for PP/LDPE blends

The transient uniaxial elongational viscosity for binary blends composed of polypropylene (PP) and low-density polyethylene (LDPE) was evaluated. A strain hardening behavior is detected for the blends, although LDPE is a dispersed phase. This behavior is attributed to LDPE dispersion deformation; the LDPE forms rigid fibers because of strain hardening. Rheological properties are calculated numerically by the Phan–Thien Tanner model by assuming a symmetric geometry with a periodic structure. Based on the simulation, we propose an appropriate LDPE to modify the processability of PP, at which the strain hardening in the elongational viscosity is required