Preparation of polybutadiene latex

The reaction is conducted by introducing the butadiene monomer, emulsifier, initiator, and chain transfer agent into the batch reactor and then elevating the temperature while stirring the reaction mixture. The ratio of butadiene to water is generally about 1 1. The emulsifier is added in the ratio of about 1 to 5 parts with respect to 100 parts of butadiene monomer, and it is used in the form of the salt of rosin or fatty soap. After the grafting reaction, the emulsifier, which can have the agglomerating property for acid or salt, is used. 

As the reaction initiator, water-soluble initiators such as KPS or oil-soluble initiators using a redox system can be used. The use of oil-soluble initiator can provide high reaction rate at relatively low temperature compared to the use of water-soluble initiator. 

The particle size can be controlled by the ratio between monomer and water as used, reaction temperature, etc. The chain transfer agent is used to control the cross-linking density of polybutadiene rubber, which greatly influences the properties of the final ABS polymer. In general, the cross-linking density is controlled to be at least 60%. After completion of the reaction, unreacted butadiene monomer is recovered and reused in the polymerization reaction. 

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