A comprehensive model for kinetics and development of film structure in interfacial polycondensation

A detailed model for interfacial polycondensation (IP) reaction, which accounts for the salient equilibrium and rate processes in reaction and phase separation, is reported here. The modeling of nucleation phenomena is more rational and fundamentally based than so far attempted in the literature on this process. Simpler models are proposed for situations in which one of transport and reaction resistances is the dominant one, and criteria developed that guide the selection of the model. The model explains the empirical findings on different interfacial systems, which have been reported in the literature. An extensive parametric study has been carried out in order to explain the effect of the important dimensionless parameters that arise, and analysis shows that most of the effects observed can be rationalized with respect to certain types of asymptotic behavior. The model makes it possible to predict the time course of development of the important film properties such as thickness, MWD and crystallinity, and to relate these to the preparation conditions and system parameters, as embodied in the different dimensionless parameters. It should therefore be possible to use this model to choose synthesis conditions and system-dependent parameters to achieve desired properties.