Processing rheological properties of ethylene-vinyl alcohol copolymer/nylon 6 composites

Abstract

Ethylene-vinyl alcohol copolymer/nylon 6 (EVOH/PA6) composites were prepared by a melt blending method. The processing rheological properties of EVOH/PA6 composites were studied by advanced capillary rheometer and rotational rheometer. The relationship between viscosity and shear rate ($\mathop \gamma \limits^.$) of EVOH/PA6 composites were fitted by power law model, and the relationship between viscosity and temperature of composites were described by Arrhenius equation. The results show that the EVOH/PA6 composites are pseudoplastic fluid. Apparent viscosity (ηa) and non Newtonian constant (n) of EVOH/PA6 composites are all enhanced with the increasing contents of EVOH. In the angular frequency (ω) scan range, the storage modulus (G'), loss modulus (G″), and complex viscosity |η*| of EVOH/PA6 composites are enhanced by the addition of EVOH. Han curve, cole-cole curve and scanning electron microscope (SEM) study show that EVOH and PA6 have good compatibility. Furthermore, EVOH/PA6 composite forms a microphase separation structure when containing 15% (mass fraction) EVOH.

Keywords

• nylon 6
• ethylene-vinyl alcohol copolymer
• composite
• rheological property
• power law model
• arrhenius equation