The elastoplastic response of and moisture diffusion through a vinyl ester resin-clay nanocomposite

TL;DR

This study investigates how moisture diffuses and how the material responds elastoplastically in a vinyl ester resin-clay nanocomposite, revealing a critical filler concentration that influences molecular mobility and material behavior.

Contribution

It introduces two simple models for elastoplastic response and anomalous diffusion in nanocomposites, with parameters fitted to experimental data, highlighting the effect of filler concentration.

Findings

Existence of a critical filler concentration around 1 wt.-%

Molecular mobility decreases with clay content below critical concentration

Filler fraction has minimal effect on chain mobility above critical concentration

Abstract

Experimental data are reported on the elastoplastic response of and moisture diffusion through a vinyl ester resin-montmorillonite clay nanocomposite with various amounts of filler. Two simple models are developed for the elastoplastic behavior of a nanocomposite and for the anomalous diffusion of penetrant molecules. Adjustable parameters in the constitutive equations are found by fitting the observations. It is revealed that some critical concentration of filler exists (about 1 wt.-%): in the sub-critical region of concentrations, molecular mobility of the host polymer strongly decreases with the clay content, whereas in the post-critical domain, the filler fraction weakly affects mobility of chains.