Influence of Nanosilica Particles on Hysteresis and Stress-Induced Crystallization of Natural Rubber as Investigated by a New Real Time True Stress-True Strain Birefringence System (Paper No. 40)

摘要

In this research the influence of nanosilica particles on hysteresis and stress - induced crystallization of natural rubber compounds is described. The Birefringence Spectral System developed in our group is able to measure true stress, true strain and birefringence in real time at 0.4 sec intervals during stretching and it is sensitive enough to detect even very low values of birefringence as the ones developed in the case of rubbers. The stress optical behavior of unfilled NR compound was compared with NR compounds filled with 5 phr and 10 phr nanosilica particles. This study allowed the determination of a critical birefringence value above which it is possible to observe stress - induced crystallization in the NR compounds. The results indicate that the addition of nanosilica particles increases the true stress - true strain as well as birefringence. In addition, the critical birefringence above which the strain - induced crystallization occurs decreases in the presence of 5 phr nanosilica indicating the enhancement of crystallization process in the presence of nanosilica. It is concluded that the addition of too much nanosilica would eventually begin to hinder the strain - induced crystallization.