Investigation of the Payne effect and its temperature dependence on silica-filled polydimethylsiloxane networks.: Part I:: Experimental results

The Payne effect is studied in silica-filled polydimethylsiloxane networks, containing various silica loadings and at variable temperature. The effect of a permanent surface treatment of the silica particles, as well as the influence of the incorporation in the system of a processing aid agent, have been investigated. The amplitude of the Payne effect is reduced by introducing a permanent treatment of the silica or a processing aid. Contrary to the unfit led network which shows the typical entropic dependence of the elastic modulus, the low shear strain elastic modulus of filled networks decreases when temperature increases. When the shear strain increases, this temperature dependence becomes less and less pronounced. and reaches a plateau value at deformations above 100%.