Effects of particle size and interfacial adhesion on mechanical properties of polyethylene /ethylene vinyl alcohol copolymer /polyamide blends
Jalalifar Nadia (1), Khonakdar Hossein Ali (2)*, Ahmadi Zahed (3), Wagenknecht Udo (4), Heinrich Gert (4)
(1) Department of Polymer Engineering-Mahshahr Branch-Islamic Azad University - Mahshahr - Iran, (2) Department of Polymer Processing-Polymer and Petrochemical Institute - Tehran - Iran, (3) Color and Polymer Research Center -Amirkabir University of Technology - Tehran - Iran, (4) Leibniz-Institute of Polymer Research Dresden, D-01069 - Dresden - Germany
The effect of phase morphology and particle size on the mechanical properties of polyethylene / ethylene vinyl alcohol copolymer / polyamide (PE/EVOH/PA) 80/20 binary and ternary blends, prepared by melt blending an twin-screw extruder, was investigated while changing the weight ratio of the minority phase.
A core-shell structure and discontinuous morphology were respectively observed for the ternary and binary blends by means of scanning electron microscopy.The morphological and mechanical properties of binary and ternary blends were compared. The blends containing EVOH showed finer dispersion and improved mechanical properties due to better interfacial adhesion. The thickness of EVOH shell-forming constituent as well as the size of composite droplet were together responsible for the alteration of tensile characteristics.
Changing the processing temperature has also been taken into consideration to deepen the interpretations.
Finally different theoretical models were applied to compare the experimental results with theory.