High Strain Hysteresis Loss of Rubber Vulcanizates under Pure Shear and Constrained Extension and Influence of Filler

Abstract

Abstract An experimental analysis of hysteresis loss, hysteresis loss ratio and input energy of natural rubber (NR) and styrene-butadiene rubber (SBR) vulcanizates having variations of loading of carbon black, precipitated silica and clay has been carried out under uniaxial, pure shear and constrained extension modes over a range of extension ratios (1.0 to 2.2 and 1.2 to 4.0 in X and Y directions, respectively), number of cycles (1 to 8) and temperatures (25 to 125 °C). Hysteresis loss, hysteresis loss ratio and input energy increase with an increase in filler loading, extension ratio (in both directions) and reinforcement. These parameters decrease with an increase of temperature and number of stretch cycle. Hysteresis loss, loss ratio and input energy under constrained extension are higher than those under pure shear and uniaxial modes. NR and SBR vulcanizates show similar behavior. Universal expressions relating energy input at any extension ratio, W1, to the hysteresis loss (Hy) as well as hysteresis loss ratio (Hy)r under uniaxial, pure shear and constrained extensions have been developed.