Emulsion polymerisation in a continuous flow stirred reactor
An investigation of the emulsion polymerisation of styrene in an isothermal continuous flow stirred reactor has been carried out. The important phenomena of sustainable oscillations and large conversion overshoot after start-up have been studied. Experimental studies have shown that conversion, number of polymer particles, molecular weights, and all other related properties often oscillate widely with time, and a steady state was not always achieved. The effect of start-up procedures in continuous emulsion polymerisation reactors have not previously beer. investigated in detail. Different start-up procedures were studied to determine their effect on the behaviour of the reactor. The effects of the initial concentration of soap and initiator, and the initial reaction temperatures have been studied experimentally in relation to the mean residence time of the reactor. Changes in start-up procedures were found to have a significant effect not only on the transients before a steady state, but also on the ultimate state achieved. Evidence was obtained supporting the theory that monomer droplets can be a locus of initiation and propagation in emulsion polymerisation of styrene in a CFSR at high level of conversion. Two possible mechanisms have been proposed to explain the phenomena of the high levels of conversion in the CFSR. Special reactor design was used to minimize aeration and to allow the variation of the average residence time without varying the pump settings.