On the reliability of existing theoretical models in anticipating type of morphology and domain size in HDPE/PA-6/EVOH ternary blends

Abstract

The evolution of morphology and domain size in HDPE/PA-6/EVOH ternary blends is comprehensively discussed. By changing the matrix type and concentration of the minor components, a variety of binary and ternary systems were prepared leading to formation of different microstructures comprising core–shell and/or individually disperse particles. The Spreading Coefficient (SC), Relative Interfacial Energy (RIE), and Dynamic Interfacial Energy (DIE) conceptual models were employed to anticipate the type of morphology in the assigned ternary systems. Due to some assumption involved in the original DIE model it was found to be unable to predict the type of morphology when HDPE was the matrix phase. For this reason, the predictability of DIE model was extended revising the dynamic interfacial tension concept. Also, a dimensionless parameter is simply defined for the purpose of enabling the estimation of core–shell size in terms of viscosity ratio and elasticity ratio over the whole composition range in the composite droplet. A more precise monitoring of particle size alteration, following the qualitative analysis of SEM micrographs after treatment with suitable solvents, indeed provides clear insight into the development of microstructure in the HDPE/PA-6/EVOH ternary blends.