Start-up procedures for continuous flow emulsion polymerization reactors

Experiments have been carried out using a continuous flow back-mixed emulsion polymerization reactor. Styrene was used as monomer. Particular attention was given to the effects of start-up procedure on reactor behaviour. Steady feed rates were not always accompanied by steady conversions of monomer. In some cases, especially at high initiator concentrations, oscillations occurred in the conversion. For a given feed composition and space time changes i start-up procedure could affect both transient and long term reactor behaviour. In some cases eventual conversions could be tripled by changing the sta procedure. When conversions reached a high and near-constant value, significant increases in the average size of polymer particles could still occur. T was accompanied by an increase in the average number of radicals per particle. The results cannot be described by simple reactor models and it is sugge that more than one process for particle formation might be operative.