On the Preparation and the Characterization of Polyethylene/Polyamide Blends by Melt Processing in the Presence of an Ethylene(co)acrylic Acid Copolymer and of New Phosphazene Compounds

Abstract

Samples of HDPE and PA6 have been meltprocessed in the presence of two new phosphazene compounds, CP-2EPOX and CP-2OXA together with an ethylene/ acrylic acid copolymer. The blends have been prepared in an industrial twin-screw extruder by using PA6 and PE in weight ratios of 25/75 and 75/25. When used, 5 phr of EAA and 0.2 phr of CP have been added. The materials have been completely characterized from a rheological, morphological, and mechanical point of view. The results indicate that the additives used caused an increase in the rupture tensile properties, of the impact strength and viscosity especially in the PE-rich blend in the presence of CP-2EPOX. This result can be attributed both to a chain extension reaction on EAA and PA6 phases and on compatibilization effect due to the possible formation of EAA-g-PA6 copolymers. This latter occurrence is suggested by an improved adhesion between the phases and by an increased turbidity observed in the Molau tests. Between the two compatibilizers, the CP-2EPOX displays the overall best results, especially for the PE-based blends.