Strain- and field-induced anisotropy in hybrid elastomers with elongated filler nanoparticles

The Effect of Particle-Matrix Interface on the Local Mechanical Properties of Filled Polymer Composites: Simulations and Theoretical Analysis

A finite element model of the local mechanical response of a filled polymer composite to uniaxial compression is presented. The interfacial layer between filler particles and polymer matrix is explicitly modeled as a third phase of the composite. Unit cells containing one or several anisometric filler particles surrounded by interface shells are considered. The dependence of the mechanical response of the cells to external deformation on the interface thickness and stiffness is studied. The use of the particle-matrix interface as a damping tool in mesoscopic polymer-composite problems with large deformations is discussed. The influence of the interface on the anisotropy of the composite response is considered.

Effects of Filler Anisometry on the Mechanical Response of a Magnetoactive Elastomer Cell: A Single-Inclusion Modeling Approach

A finite-element model of the mechanical response of a magnetoactive elastomer (MAE) volume element is presented. Unit cells containing a single ferromagnetic inclusion with geometric and magnetic anisotropy are considered. The equilibrium state of the cell is calculated using the finite-element method and cell energy minimization. The response of the cell to three different excitation modes is studied: inclusion rotation, inclusion translation, and uniaxial cell stress. The influence of the magnetic properties of the filler particles on the equilibrium state of the MAE cell is considered. The dependence of the mechanical response of the cell on the filler concentration and inclusion anisometry is calculated and analyzed. Optimal filler shapes for maximizing the magnetic response of the MAE are discussed.

A simple, efficient route to modify the properties of epoxy dynamic polymer networks

A simple and efficient strategy to modify epoxy dynamic polymer networks (DPNs) is presented. The introduction of the flexible epoxidized form of naturally occurring soybean oil (ESO) into epoxy DPNs markedly improves their mechanical properties, stress relaxation rate and malleability. Specifically, at 7.5 wt% ESO loading, the elongation at break of the as-produced epoxy-ESO DPNs was increased from 10% to 108%, the stress relaxation time decreased from 6100 s to 2570 s at 120 °C, and the reprocessing temperature was reduced by 26 °C, which is advantageous for expanding the scope of applications of these materials, especially for reducing the energy consumption during reprocessing. At this composition, the epoxy-ESO DPNs also showed excellent self-healing, welding and chemical degradation properties. This work provides a novel pathway to fabricate epoxy-based DPNs with high performance in an energy-conserving manner.