Particles in model filled rubber: Dispersion and mechanical properties

Abstract

We have been able to design model filled rubbers with exactly the same chemical structure but different filler arrangements. From these model systems, we show that the particle arrangement in the elastomeric matrix controls the strain softening at small strain amplitude known as the Payne effect, as well as the elastic modulus dependence on the temperature. More precisely, we observed that the Payne effect disappears and the elastic modulus only weakly depends on the temperature when the particles are well separated. On the contrary, samples with the same interfacial physical chemistry but with aggregated particles show large amplitudes of the Payne effect and their elastic modulus decreases significantly with the temperature. We discuss these effects in terms of glassy bridge formation between filler particles. The observed effects provide evidence that glassy bridges play a key role on the mechanical properties of filled rubbers.

Hyperelasticity with rate-independent microsphere hysteresis model for rubberlike materials

“…Similarly to the other elastomers, silica filled silicone rubbers exhibit a hysteresis loop in terms of the stress-strain relationship [7]. The hysteresis loop is not observed when the silicone rubber is unfilled [7], showing that hysteresis is not due to macromolecular network deformation but to fillers, more especially to interactions between fillers and rubber matrix [23]. Similar results are observed in other elastomers, for which hysteresis can also be wrongly attributed to viscosity.…”

Depercolation of aggregates upon polymer grafting in simplified industrial nanocomposites studied with dielectric spectroscopy

“…the dispersion state of the nanoparticles (NPs), which may be individually dispersed, organized in small aggregates, or form sample-spanning networks of percolated particles or aggregates. [6][7][8][9][10] The microstructure sets the frame for the dynamical properties, which themselves control many macroscopic properties, like, e.g., the time-dependent reaction of samples to mechanical stress which is often based on structural reorganization [11,12].…”

Confinement-Induced Stiffening of Thin Elastomer Films: Linear and Nonlinear Mechanics vs Local Dynamics

“…This macroscopic reinforcement of filled elastomers has been widely used in many technological applications. 8−10 Nevertheless, and despite extensive work in the field within the past years, the origin of the reinforcement and its sensitive dependence on filler volume fraction, 7 dispersion, 11 and interfacial energy 12,13 has not yet been completely understood. This is of great importance, in view of the nonlinear mechanical behavior, in which a rapid drop of reinforcement is observed already at small deformation amplitudes (the so-called Payne effect 14 ).…”