Filler-induced deformations of amorphous polyethylene chains. the effects of the deformations on elastomeric properties, and some comparisons with experiments

Monte Carlo simulations based on rotational isomeric state models were carried out to determine how amorphous polyethylene chains are deformed by the presence of spherical filler particles. The resulting distributions of the chain end-to-end distances were then employed to calculate mechanical properties of the cross-linked chains. The basic goals were (i) to refine previous simulations of this type carried out on this system to remove possible sampling biases, and (ii) to document the circumstances under which the particles stretch the chains to larger end-to-end distances, rather than compress them to smaller distances, and (iii) to study in more detail the flattening of the chains near particle surfaces. Comparisons with experiments include filler-induced changes in chain dimensions measured by neutron scattering, and general features of the stress-strain isotherms widely observed for reinforced elastomers in simple elongation.