Modeling of steady and time-dependent responses in filled, uncured, and crosslinked rubbers

Filled polymer systems have been a subject of interest for rheologists for several decades. Their applications range from paints and pigments to high performance composite materials. Presently, there is a lack of complete understanding of the behavior of these materials under varying kinematic and dynamic conditions. Moreover, there is a lack of a comprehensive theory, which can simultaneously describe the rheology of filled rubbers, their chemorheology, and their behavior in the final fully cured state. The present work is aimed at capturing a wide range of rheological (viscoelastic and kinetic) properties of filled rubbers with one set of constitutive/kinetic equations and a flexible relaxation spectrum. The various experiments covered are yield-flow transition in creep, shear start up responses, dynamic behavior in the melt state, and the changes during the cure stage. In the post cure state, the manifestations in Mullins stress softening-hysteresis and recovery, large strain stress relaxations, and dynamic behavior are also demonstrated. Finally, the non-linearities during large strain dynamic deformations, accompanied by non-isothermal, viscoelastic, and structure effects are exemplified.