THE EFFECT OF TEMPERATURE AND INITIATOR LEVELS ON THE DISPERSION POLYMERIZATION OF POLYSTYRENE

Considerable interest has been generated recently by the preparation of large monodisperse polymer latices by a multistage swelling process. Dispersion polymerization in organic media has been shown to be an alternative route to the preparation of large monodisperse polymer colloids. The temperature affects both the rate of free radical formation and the thermodynamic properties of the polymerization system. It is shown that monodispersity can be achieved over a considerable range of temperatures provided that a particular level of initiator is used at a given temperature. It is also shown that higher levels of initiator at a particular temperature actually produced larger particles. However, the level of initiator was not found to significantly change the overall rate of polymerization.