Time-concentration superpositioning principle accounting for the reinforcement and dissipation of high-density polyethylene composites melts

The filler reinforcement effect has been extensively investigated for the better part of a century while most of the conclusions are ambiguous without specifying the “frequency”-dependent polymer dynamics. Herein a recently proposed time-concentration superpositioning principle, disclosing a unique hydrodynamic-to-non-hydrodynamic transition with respect to filler loading and frequency, is examined in the linear rheology of multi-walled carbon nanotubes, carbon black and silica filled high-density polyethylene composites. The results suggest that the filler topology and filler-polymer interaction strongly influence the strain amplification effect, the dynamics retardation in the bulk phase and the critical filler concentration defining the hydrodynamic-to-non-hydrodynamic transition of the composites. The new findings may open a way for quantitative assessment of the roles played by the polymer, the filler and their interfacial interactions to the composites' rheology.