Effect of surfactants on the properties of rubber composites prepared from pyrolytic carbon black/natural latex via wet blending method

Pyrolytic carbon black (CBp) is the main by-product of waste tire pyrolysis. CBp has high ash content and poor surface activity which leads to the composites reinforced with CBp has lower performance than composites reinforced with commercial carbon black, making it difficult to meet the requirements of tire. In order to realize the application of CBp in tires, the effect of surfactants on the properties of rubber composites prepared by wet mixing of CBp/natural latex was investigated. In the experimental process, sodium stearate (C 17 H 35 COONa), sodium dodecylbenzene sulfonate (C 18 H 29 NaO 3 S), and sodium p-styrenesulfonate (C 8 H 7 NaO 3 S) were used to improve the surface activity and uniform dispersion of the CBp in the natural rubber matrix. The experimental results showed that the dispersity of C 18 H 29 NaO 3 S and C 8 H 7 NaO 3 S modified CBp in rubber matrix has [X] and [Y] values of 7.5 and 7.9, and 9.3 and 9.5, respectively, and the dispersion of these rubber composites is significantly better than that of C 17 H 35 COONa. The rubber composites prepared by C 18 H 29 NaO 3 S and C 8 H 7 NaO 3 S surfactants has the better physical and mechanical properties. The rubber composite prepared by C 18 H 29 NaO 3 S has the highest tensile strength of 25.63 MPa, which increment in tensile strength is 15.6% compare to the rubber composite prepared by C 17 H 35 COONa. Meanwhile the dynamic mechanical properties of rubber composites prepared by modifying CBp with C 18 H 29 NaO 3 S and C 8 H 7 NaO 3 S are better than CBp with C 17 H 35 COONa. The C 8 H 7 NaO 3 S modified CBp/rubber composite has the lowest loss factor (tanδ) value at 60°C, and the C 18 H 29 NaO 3 S modified CBp/rubber composite has the highest tanδ value at 0°C.