Nucleation in heterophase polymerizations

It is desirable to assess whether the final particle number in heterogeneou s polymerizations is predetermined by the number of monomer droplets. If th is is really the case nucleation occurs very smoothly via a polymer in mono mer solution where the kinetically important step is the initiation reactio n inside the droplets. However in the case of emulsion and dispersion polym erizations the nucleation step is a sharp phase transition when the free po lymer phase is formed in the continuous phase. This process can be describe d generally with the classical nucleation theory although it is today not y et possible to give quantitative explanations for some new experimental res ults. These new experimental results prove the strong influence the kind of the reactor material as well as the stirrer speed has on particle nucleati on and final latex properties.