Investigation Of Dynamic Fatigue Performance In Carbon Black Filled NR And NR/SIBR Blends

The evolution of dynamic mechanical properties and physical mechanical properties with increase of fatigue degree was investigated deeply for carbon black (CB) filled NR vulcanizates by means of changing carbon black content. The results showed that the fatigue life of carbon black filled NR vulcanizates decreased linearly with increase of carbon black content. The arrangement of carbon black aggregates was random catenation in the plane, which was perpendicular to the stretching direction. The filler network was destroyed at the first stage of fatigue process, however, the destruction of filler-polymer interaction lasted during the fatigue process. The peak of loss modulus decreased after fatigue, and it shifted to large strain with increase of fatigue degree.The evolution of dynamic mechanical properties and physical mechanical properties with increase of fatigue degree was investigated deeply for carbon black filled NR/SIBR by means of changing the ratio between NR and SIBR. The results showed that the fatigue life of samples decreased with increase of NR content in terms of power-exponential function, and the decreasing amplitude was slow with increase of NR content. For the samples with different ratios between NR and SIBR, the decreasing amplitude of storage modulus increased with increase of fatigue time, increasing with NR content. The storage modulus of rubbery state was the highest, when the ratio between NR and SIBR was 1:1. With increase of SIBR content, the fatigue degree increased, when the decrease of AE’ appeared obviously. The loss factor decreased with increase of NR content.The evolution of dynamic mechanical properties and physical mechanical properties with increase of fatigue degree was investigated in detail for carbon black filled NR/SIBR by means of changing carbon black content and keeping the ratio between NR/SIBR constantly. The results showed that the fatigue life of samples decreased with increase of carbon black content in terms of power-exponential function, and the decreasing amplitude was slow with increase of carbon black content. The glass transition temperature of NR shifted to high temperature with increase of carbon black content, however, the glass transition temperature of SIBR was almost invariable. For the vulcanizates filled with 50phr carbon black, the loss factor decreased at the same temperature with increase of fatigue degree, and the temperature-dependence of the loss factor increased for the samples after fatigue. For the vulcanizates filled with 70phr carbon black, the storage modulus at low strain decreased, when the fatigue degree was 40%, however, the storage modulus at low strain increased, when the fatigue degree was 98%, but it was lower than that of the initial sample.