Rheological and Mechanical Properties of Poly(ethylene acrylic acid) and Low Density Polyethylene Blends

Rheological properties of poly (ethylene-acrylic acid) (PEA) and low density poly ethylene (LDPE) blends having varied amounts of LDPE from 0 to 100% have been evaluated at different temperatures (115, 120, and 130 degrees C) and shear rates (61.33-613.30 s(-1)) using a Monsanto processability tester. A reduction in the melt viscosity of the PEA/LDPE blends was noticed with increasing the shear rate. The observed positive deviation in the experimental melt viscosities of the blends is an indication of the synergy present in the blends during melt processing. The activation energy (E(a)) of flow calculated using Arrhenius relation for PEA, LDPE, and their respective blends lies in the range 29.98-40.56 kJ mol(-1). The experimental activation energy of flow of the blends was higher than that obtained from the additivity rule. Highest activation energy was noticed for the blends containing 60-80% by weight of LDPE in PEA/LDPE blends, which is an indication for the miscibility of the blends at these ratios. The physicomechanical properties such as density, tensile behavior, tear strength, and hardness (Shore A) of PEA, LDPE, and their blends have been evaluated as a function of varying amounts of LDPE. The obtained physicomechanical properties of the PEA/LDPE blends lie in between that of pure polymers. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 3070-3077, 2011