Study On The Relationship Between Filler Dispersion And Payne Effect In NR/Carbon Black Composites

The Payne effect, essentially is the phenomenon that the modulus of rubber compounds non-linearly decrease with increasing strain amplitude. The mechanism of Payne effect has so many interpretation, with filler-filler network destroyed most representative. It use the difference of elastic modulus of the rubber compound, which is between low amplitude and high amplitude, to reflect filler-filler interaction. Some researchers used the Payne effect to characterize the dispersion of filler in the compounds, which is under the premise of ignoring molecular weight of rubber. In fact, the molecular chains can occur disentangled, orientation and other processes during increasing amplitude, which will have an impact on the elastic modulus. In this paper, we change the dispersion of filler and control the same molecular weight of rubber and study the filler dispersion relations with Payne effect under this premise.This article was prepared NR/carbon composites by emulsion coprecipitation, which has same molecular weight and different dispersion of filler. By thermal gravimetric analysis (TGA), Mooney viscometer, ZETA SIZER Nano-ZS90 particle size analyzer, scanning electron microscopy (SEM), RPA2000 such as testing instruments, we had researched the dispersion of carbon black and its influence on dynamic performance and filler network. We had explored the relationship between the dispersion of carbon black and Payne effect, to describe the relationship between the dispersion of carbon black and filler-filler interaction.The results show that:(1) We had conducted the deformation, temperature and frequency scanning to raw NR and pure rubber vulcanized by RPA2000.The results show that the elastic modulus of rubber, what is the raw NR and pure rubber compounds masticating different times, show the phenomenon of non-linearly decrease with increasing strain amplitude; With the increasing mastication times of raw NR and pure rubber compounds, what decreased the molecular weight of rubber, the elastic modulus decreased gradually on low strain. This shows that the molecular weight of rubber has the influence on the elastic modulus of compounds. The lower the molecular weight of rubber is, the smaller the elastic modulus.(2) We had prepared NR/carbon composites by emulsion coprecipitation, which has same molecular weight and different dispersion of filler, and test it by scanning electron microscopy(SEM), Mooney viscometer, RPA2000 and so on. The results shows that:In NR/carbon black composites, the Mooney viscosity increased with the increasing of the dispersion of carbon black; The elastic modulus of compounds with different dispersion showed the phenomenon of non-linearly decreased with increasing strain amplitude; And with the increasing dispersibility of carbon black, the elastic modulus of compounds decreased gradually at low strain, which shows that the dispersion of carbon black has the influence on the elastic modulus of compounds. The larger the dispersion of carbon black is, the smaller the elastic modulus.(3) We had prepared NR/carbon composites by emulsion coprecipitation, which has same molecular weight and different content of carbon black, and test it by scanning electron microscopy(SEM), Mooney viscometer, RPA2000 and so on. The results shows that:In NR/carbon black composites, the dispersion of carbon black decreased and the Mooney viscosity increased with the increasing content of carbon black. The elastic modulus of compounds with different content of carbon black showed the phenomenon of non-linearly decreased with increasing strain amplitude; With the increasing content of carbon black, the dispersibility decreased,the elastic modulus increased gradually at low strain and Payne effect increased.