Monitoring of Emulsion Polymerisation Processes using Ion Mobility Spectrometry—A Pilot Study

Online monitoring of monomer concentrations in (semi‐) batch emulsion polymerisation reactors is important for safe and cost‐efficient operation of production plants. In the present pilot study, ion mobility spectrometry was applied for monitoring the concentration during emulsion polymerisation of vinyl acetate (VA) using UV light for ionisation of the headspace of a continuous sample flow. Satisfactory sensitivity for online process monitoring of the monomer concentration in the reactor was observed (LOD 400 ng · L−1 air, equivalent to <1%). Furthermore, it is possible to discriminate between VA and other common monomers [butyl acrylate (BA), methyl methacrylate (MMA)]. Using the more efficient β‐radiation ionisation, monomer concentration could be measured even in the final latex as a measure of the final product properties. magnified image