Absolute online monitoring of a stepwise polymerization reaction: Polyurethane synthesis

Abstract

AbstractThe feasibility of using a recently introduced method for continuous, absolute online monitoring for step‐growth polymerization was demonstrated, and polyurethane synthesis was chosen for the demonstration. The previously reported use of this method was for monitoring free‐radical initiated chain‐growth polymerization. The technique involves continuously withdrawing a small stream of reaction liquid from the polymerization reactor and pumping it through a series of light scattering and viscosity detectors. This permits the absolute weight‐average molecular weight and reduced viscosity to be simultaneously monitored as the reaction proceeds. The final weight‐average molecular weights of the polyurethane samples were compared to the separate light scattering measurements of the final products. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2070–2077, 2001