New insights into kinetics and thermodynamics of interfacial polymerization

A comprehensive model is developed for interfacial polymerization (IP), which provides new insights into the kinetics of him formation, the molecular weight distribution of the polymer as well as the mechanism of polymer precipitation. We incorporate a more general reaction scheme as well as polymer phase separation both by nucleation of the polymer-rich phase as well as by spinodal decomposition. The model predictions are verified against experimental data for unstirred Nylon 6-10 system. The model predicts that spinodal decomposition is the dominant mechanism of polymer phase separation at short reaction times. Film growth by nucleation of the polymer-rich phase dominates at larger times. The model also predicts the dominance of the nucleation mode of film growth with dilution of the organic phase. This model provides a further step towards a rational design and prediction of properties of membranes/capsules produced by interfacial polymerization. (C) 1998 Elsevier Science Ltd. All rights reserved.