MOLECULAR TREATMENT OF RUBBER-LIKE ELASTICITY FOR ACTIVE FILLER–LOADED NETWORKS

Abstract

ABSTRACT Prior comparison of experimental observations and model predictions for natural rubber/styrene–butadiene rubber carbon black–filled systems has indicated a need for further development of tubelike constraint-based entropy models. In particular, systems incorporating active fillers introduce constraints whose effects should be considered. This contribution extends the finite-extension single-chain model proposed originally by Teramoto, via consideration of the bound rubber layer surrounding a filler particle as well as filler-cluster breakup and strain-amplification effects. The resulting model includes descriptors of the entropy state of the polymer matrix, the affine and phantomlike chain deformation, and tube diameter. The model produced a more accurate prediction of the shape of observed stress–strain curves, particularly at moderate and high strains.