E. I. du Pont de Nemours and Company, Experimental Station, Wilmington, DE 19880, USA
Abstract:
A reaction mechanism for the polymerization of 1,3‐propanediol is proposed for two acid catalysts. Population and mass balance equations are derived for small molecules and for polymeric species of chain distributions distinguishable in terms of protonation state and end group functionality. Since the sulfuric acid catalyzed process has two types of polymer linkages, the derivation of the moment equations is challenging. The reverse reactions are also accounted thus creating a moment closure problem. A mass transfer model is developed to predict reaction mixture water content. The Sanchez‐Lacombe equation of state is used to calculate phase behavior and species partitioning. Optimization of selected parameters is accomplished by comparison to laboratory data resulting in a fully predictive model.
