On the Emergence of the Payne Effect in Polymer Melts Reinforced with Nanoparticles

Abstract

This study presents a molecular model for the amplitude‐dependent dynamic moduli of polymer melts reinforced with nanoparticles. This study shows that intense strain‐thinning reported in experimental studies of polymer nanocomposites can be attributed to disentanglement of bulk polymer chains from those strongly adsorbed to the surface of nanoparticles. This flow‐induced relaxation is what is frequently termed as convective constraint release and is similar to the cohesive slip of polymer melt at solid interfaces.

Dynamics of entangled polymer chains with nanoparticle attachment under large amplitude oscillatory shear

“…The qualitative trends in both parameters are preserved with an increase in the CCR parameter: an increase in the power law exponent of I 3/1 with strain amplitude and the presence of an overshoot in Q . The case of uniform CCR parameters was also examined by Sarvestani in his model computations, which showed increasing nonlinearity at higher CCR.…”

“…The minimum is observed only for well separated relaxation times—when the particle–polymer interactions are strong. A comparison of Q 0 between double reptation averaging used in this work and the linear averaging presented by Sarvestani is made for ϕ a = 0.1 and c = 20, shown in Figure . Both linear averaging and double reptation generate a peak in Q 0 .…”

“…The dynamics of a mixture of free polymer chains and polymer chains attached to nanoparticles has been modeled recently by Sarvestani . The stress was obtained by linear averaging over volume fractions ( ϕ ) of the two types of chains denoted by the indices f and a .…”

“…The present work seeks to address two limitations of the mixture model presented by Sarvestani . First, linear averaging over volume fraction is inconsistent with the double reptation formulation of the Marrucci–Ianniruberto model required for representing the mixture of chains.…”

Towards the Development of a Strategy to Characterize and Model the Rheological Behavior of Filled, Uncured Rubber Compounds

“…Agglomerate ∼ 1 − 10 µm Primary aggregate ∼ 100 nm Primary particle ∼ 10 nm The Payne effect has been attributed to several mechanisms, such as the agglomeration/deagglomeration of filler aggregates, breakup/reformation of the filler-filler and polymer-filler network [12,13], chain desorption from the fillers [14], yielding of the glassy layer between the fillers [15] and disentanglement of the absorbed chains [16].…”