On-line control of particle morphology of waterborne dispersed polymers using master trajectories

Abstract

On-line control of the morphology of waterborne composite latex particles is an unsolved issue because of the lack of techniques for on-line monitoring of particle structure. As an alternative to online monitoring, soft sensors based on detailed mathematical models for the development of particle morphology can be used but they require knowledge of a large number of system-specific parameters and, therefore, they are not suitable for a market characterized by large portfolios of products. This work presents a new method to achieve control over final particle morphology by using master trajectories obtained from a given reference process as set points. The master trajectories are derived from the understanding of the fundamental phase separation and phase migration processes occurring during the development of the particle morphology, and can be estimated during the process from available on-line measurements (overall and instantaneous monomer conversion, and reactor temperature). The approach opens the way to on-line control of the particle morphology and can also be used for process optimization.