Prediction of the viscoelastic response of filler network in highly nanofilled polymer composites

An accurate prediction of any process is the key to the control of that system. Modeling the rheological properties of nanocomposites would provide us a pattern for prediction of their properties as a function of process and material variables. In this study, the focus is to model and investigate the behavior of highly nanofilled systems, which is controlled by the filler–polymer and filler–filler interactions. In these systems, particles attract each other and form a network, which has a viscoelastic response to the applied stress or strain. Due to the filler–polymer interaction, polymer chains are adsorbed on the filler surface to create a secondary network, parallel with the filler–filler network. The third network in the system is the network of free polymer chains around the adsorbed ones. In this work, the behavior and contribution of these networks in the highly nanofilled systems are described. Furthermore, the relaxation time and the modulus of the filler network are estimated as a function of particle size and concentration. It is observed that the relaxation time and modulus of the filler network are increased with a reduction in particle size and an increase in particle concentration. For studying the parameters of the model, polymer adsorbed layer and available surface area of particles are estimated from the density of the nanocomposites.