Particles in model filled rubber: dispersion and mechanical properties.

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Filled rubbers are widely used polymers with enhanced properties due to filler particles.
• Understanding filler-particle interactions is crucial for optimizing rubber performance.
• The Payne effect and temperature dependence of modulus are key mechanical characteristics of filled rubbers.

Purpose of the Study:

• To investigate the influence of filler particle arrangement on the Payne effect and temperature dependence of the elastic modulus in model filled rubbers.
• To elucidate the role of filler aggregation and interparticle interactions in determining mechanical properties.
• To provide evidence for the contribution of glassy bridges to the behavior of filled rubbers.

Main Methods:

• Design of model filled rubber systems with identical chemical structures but varied filler arrangements.
• Characterization of Payne effect (strain softening at small strain amplitudes).
• Measurement of elastic modulus dependence on temperature.

Main Results:

• Well-separated filler particles eliminated the Payne effect and minimized temperature dependence of the elastic modulus.
• Aggregated filler particles exhibited significant Payne effect and a pronounced decrease in elastic modulus with increasing temperature.
• These distinct behaviors were correlated with the presence or absence of interparticle glassy bridges.

Conclusions:

• Particle arrangement in the elastomeric matrix is a critical determinant of the Payne effect and temperature-dependent elastic modulus.
• Aggregated filler particles, forming glassy bridges, lead to significant Payne effect and temperature sensitivity.
• The findings highlight the crucial role of glassy bridges in dictating the mechanical properties of filled rubbers.