Optimization of Rubber Binder Viscosity

Since viscosity is a very important parameter characterizing every liquid rubber and influencing the main physical and mechanical properties of the projected composite, it frequently determines the choice of the polymer and reasonability of its use. The industry manufactures rubbers with viscosity varied in large spectrum (e.g., for polybutadiene PBN, that interval is [(0.2 A 7.1) Pa - s]). However, there is no data that allows estimation of the viscosity of rubber that is useful in RubCon compositions. 

A series of experiments were carried out to evaluate the value of the viscosity of rubber allowing the needed varied parameter has been viscosity, and the measured function — the RubCon durability against compression and bending. The experiment used PBN rubber with viscosities (Pa s) of 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, and 2.2. The regression analysis of the obtained results allowed deduction of mathematical models that adequately describe the correlation of the durability of the samples to compression and bending  

FIGURE 2.2 Stresses ocom and O, of RubCon depend on amount of rubber viscosity. (Reprinted from O. Figovsky and D. Beilin, Building Materials Based on Advanced Polymer Matrix Review, J. Scientific Israel Technological Advantages 10, no. 3 (2008) 1-119. With permission.) 

This is probably explained by the hardness of RubCon prepared from rubber with viscosity 1.6 Pa s in comparison with that from rubber with viscosity 1.2 Pa s, because the density of linkage is higher for a polymer with higher molecular mass related to viscosity. 

Based on these results, we can conclude that the value of optimal viscosity of low-molecular polybutadiene with mixed microstructure, involved in the RubCon mixture, is in an interval from 1.1 to 1.7 Pa s. The further studies employed rubber with viscosity 1.5 Pa s. 

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