Improve The Conversion Rate Of Sbr

In the conventional Styrene-Butadiene Rubber(SBR) emulsion polymerization process, the conversion of monomers were low and some toxic substance would release such as nitrosamines compounds in the later process. It is important to improve the low conversion issue and find an environmentally friendly SBR synthesis technology.The SBR emulsion polymerization process was first studied by using a standard formula. Results showed that the combining styrene content was 23.8% when the conversion reached 70%, and the combining styrene content meet the specifications of the national SBR product standard. However, Mooney viscosity of the product was 80, 38% higher than the national product standard limitation.In order to improving the issue of Mooney viscosity, Monte-Carlo method was used to simulate the SBR emulsion polymerization. Results showed that the Mooney viscosity could be reduced by increasing the amount of emulsifier and initiator. These methods could improve the number of particles, and the molecular weight distribution become narrow when the conversion reached by 70%.Based on the simulation results, the polymerization formula was improved by changing the adding amount of emulsifier and polymerization initiator. This formulation gave a good Mooney viscosity when the reaction time was 10h and the conversion reached by 70%. Results also showed that the combining styrene content in product was 22.7%, and the Mooney viscosity was 53.Finally, a new terminator was investigated for preventing the emission of toxic materials. Results showed that no volatile nitrosamine compounds were released in the polymerization process. The vulcanized performance, physical performance and processing performance could also reach or overmatch the performances of the conventional SBR.