Assessing robustness of hyperelastic models for describing nonlinearity of the mechanical response for pristine and swollen carbon black filled elastomers

Abstract

We consider the hyperelastic response of semi‐crystalline ethylene–co‐butyl acrylate (EBA) samples filled with carbon black (CB) particles. Such material is structurally complex with its microstructure being characterized by many structural parameters including crosslink density, filler/matrix interfaces, crystallinity, filler network, and chain entanglement which have different degrees of influence on the effective mechanical properties. We evaluate the ability of a number of analytical models to correctly reproduce the non‐linear elastic mechanical response of these samples. We do this by considering either dry samples, or samples which are swollen by a non‐polar solvent (toluene) at equilibrium, and subjected to uniaxial tension at room temperature. As test cases, we focus on six physical models for the purpose of analyzing the stress–strain curves of samples with different cross‐linking densities. Among these frameworks, we show that the Mooney–Rivlin (MR), Ogden, and eight‐chain models accurately describe the stress–strain curves of both dry and swollen CB‐EBA samples. These findings highlight the possibility of attaining a diverse set of mechanical properties of filled polymer samples by tailoring their structural parameters.