Remote, in-line monitoring of emulsion polymerization of styrene by short-wavelength near-infrared spectroscopy .2. Performance in the face of process upsets

This work is a continuation of previous research on monitoring of emulsion polymerization of styrene by short-wavelength near-infrared spectroscopy (SW-NIR). In order to test the monitoring system during a process upset, various disturbances are introduced. These include: pulse addition of monomer, change in temperature, and temporary loss of agitation. For these studies, the results are rationalized in two ways: (a) computer simulation of the changes in concentration by numerical integration of a process model based on first principles, and (b) curve fitting of Be spectra to a basis set of pure monomer, polymer, and water spectra, Spectroscopic monitoring is further improved by the use of simulation data as reference values to build more accurate principal component regression (PCR) and partial least squares (PLS) models, It is shown that NIR spectroscopy can provide valuable information on the status of an emulsion polymerization process.