Filler Network Analysis

Correspondence between nonlinear viscoelastic properties and change in various networks in carbon black filled SBRs has been studied by using combined measurements of relaxation modulus and volume resisitivity in wide range of filler concentrations at various shear strains. Volume resistivity at no deformation showed step-off like change which can be explained by the percolation theory. This indicates formation of contact filler network at high filler loading. In addition, change in volume resistivity showed clear correspondence with linear-nonlinear transition in viscoelasticity. By the use of simple three-network model, contributions of contact filler, bridged filler, and entanglement networks to relaxation modulus were estimated. It was found that contact filler and bridged filler networks were dominant at lower and at higher filler concentrations, respectively.