Inline Raman Spectroscopy of an Emulsion Copolymerization in an Industrial Pilot Plant Using Indirect Hard Modeling

Raman spectroscopy is used to determine the concentrations of monomers and polymers in the second stage of a two‐stage emulsion polymerization process. The indirect hard modeling (IHM) approach is applied to monitor inline the reaction in semi‐batch operation in lab scale and pilot scale. This method requires the spectra of all pure components. While the pure spectra of water and monomers are easily measured as pure components, the spectra of two different copolymers are constructed from reaction spectral data containing mixtures. Good predictive capabilities of the developed model are demonstrated. A two‐stage emulsion copolymerization process is monitored via Raman spectroscopy, both in a lab‐scale reactor and in an industrial pilot plant reactor. The Raman signals are analyzed using the indirect hard modeling approach. Good predictive capabilities of the developed model are presented.