Continuous process, dispersion polymerization-acrylonitrile

An example of a continuous aqueous dispersion process is shown in Figure 12.5 [92]. A monomer mixture composed of acrylonitrile and up to 10% of a neutral comonomer, such as methyl acrylate or vinyl acetate, is fed continuously. Polymerization is initiated by feeding aqueous solutions of potassium persulfate (oxidizer), sulfur dioxide (reducing agent), ferrous iron (promoter), and sodium bicarbonate (buffering agent). The aqueous and monomer feed... 

High-impact polystyrene and acrylonitrile-butadiene-styrene copolymer are often prepared in a combined bulk-suspension process. This begins with a solution of polybutadiene in styrene or styrene/acrylonitrile. Subsequently, the polymerization of styrene or styrene/acrylonitrile is initiated and continues under stirring until phase inversion occurs (i.e., polybutadiene is dispersed in a continuous PS matrix - Chapter 4). In the final stage, water and dispersant are added to the system and the polymerization is completed in suspension. 

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