Technology

Solution SBR is obtained by living anionic polymerization of Styrene and Butadiene in a refined hydrocarbon solvent using an alkyllithium catalyst. Impurity control is very important because the impurities in living anion greatly affect living anionic polymerization. Water and oxygen have a particularly large effect. Like ESBR, there are continuous polymerization processes and batch polymerization processes. In the continuous polymerization process, solvent, butadiene, styrene, and catalyst are continuously supplied to the reactor. In the batch polymerization process, solvent and monomers are supplied to the reactor. The main difference in physical properties depending on the polymerization process of SSBR is the molecular weight distribution and the degree of freedom in design. Polymerization terminator and anti-aging agents are added to the polymerization solution, and if necessary, extender oil is added as necessary to the solution, and the solution is sent to the desolubilization process.

In the desolubilization process, the polymerization solution is sent into hot water heated by steam, and the unreacted monomers and solvent are evaporated and recovered. Simultaneously, SBR crumbs are obtained. The resulting crumbs are sent to the drying process, dehydrated and dried, then subjected to automatically weighing, compression molded into bales, and metal detectors are used to check that there is no metal contamination. The unreacted monomers and solvents recovered in the desolubilization process are sent to the refining process, and are reused after distillation.

Source: Yutaka NAGATA, 13^th Mar 2015, Industrial Synthetic Method of the Rubbers - 3. Styrene Butadiene Rubber, The Society of Rubber Science and Technology, Japan.