Monitoring of polymer content in an emulsion polymerization using spatially resolved spectroscopy in the near infrared region and Raman spectroscopy

Abstract The potential of spatially resolved spectroscopy (SRS) for in situ monitoring is evaluated in this work. SRS is based on near‐infrared spectroscopy. It is well adapted to heterogeneous systems and collects information about both physical and chemical properties. In this work, the polymer content in emulsion copolymerization is predicted using SRS. The reaction was first carried out in batch mode for particle nucleation followed by semi‐continuous monomer addition under starved conditions to allow particle growth. SRS and Raman spectroscopy are compared, and the advantages and disadvantages of both methods are highlighted, revealing that each method has its own benefits. Different operating conditions were varied, including the monomer ratio, the surfactant mass fraction, and the agitation speed. Regression models were developed using partial least square for both techniques.