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

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 (over dot(gamma)) 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 (eta(a)) and non Newtonian constant (n) of EVOH/PA6 composites are all enhanced with the increasing contents of EVOH. In the angular frequency (w) scan range, the storage modulus (G'), loss modulus (G ''), and complex viscosity vertical bar eta vertical bar* 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.