Feasibility of simultaneous determination of monomer concentrations and particle size in emulsion polymerization using in situ Raman spectroscopy

Abstract

An immersion Raman probe was used in emulsion copolymerization reactions to measure monomer concentrations and particle size. Quantitative determination of monomer concentrations is feasible in two-monomer co-polymerizations, but only the overall conversion could be measured by Raman spectroscopy in a four-monomer co-polymerization. Feasibility of measuring monomer conversion and particle size was established using partial least square (PLS) calibration models. A simplified theoretical framework for measurement of particle sizes based on photon scattering is presented, based on the elastic sphere vibration and surface tension models.