The modeling of hydrolytic caprolactam polymerization is reviewed and a state-of-the-art mathematical model is proposed. The model includes the basic reactions of reversible ringopening, polyaddition, and polycondensation as well as the reversible formation/hydrolysis and polyaddition of cyclic oligomers. For the first time, a method is proposed to implement stabilization with acids of any functionality so that their impact on the molecular weight distribution can be analyzed. A comparison of the model predictions with experimental data taken from the literature reveals excellent agreement. As shown in this work, the proposed model for the synthesis of polyamide 6 can be used to dynamically compute the complete molecular weight distribution. Therefore, it gives access to desired product designs for this industrially important polymer. The method presented for modeling multichain hydrolysis may also be of interest for other polycondensation systems that result in star-shaped polymers.

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Summary: The effect of sodium dodecyl sulfate (SDS) on the mass transfer rate between styrene and water has been investigated. SDS increases the solubility of styrene in water even below the critical micelle concentration (CMC) and therefore increases the thermodynamic driving force for the mass transfer. The mass transfer coefficient however is not altered by SDS, even if the interface is almost saturated with emulsifier.

An experimental and theoretical study on the thermal (spontaneous) polymerization of styrene in compartmentalized systems is presented. Experimental data on thermally polymerized miniemulsions varying temperature and droplet size is provided. This data is used to test a new model approach to describe the thermal polymerization process of a disperse phase. The mathematical model is based on a chemical master equation balancing radical species that are capable of desorption (monomeric radicals) and ones that cannot leave a particle. Reasonable agreement between theory and experiment for the data provided here and for literature data can be achieved. Part 1 of this series is a review on the thermal bulk polymerization of styrene.