We have used a simplified model of emulsion polymerisation, along with an a
daptive calorimetric approach and a set of non-linear state estimators to m
onitor the individual monomer conversions in a pilot scale polymerisation r
eactor for the production of methyl methacrylate/butyl acrylate/carboxylic
acid polymers. The usefulness of reaction calorimetry for the monitoring of
such systems is demonstrated. It is also shown that non-linear, high gain
estimators can be used to monitor such systems even if they are based on si
mplified models that ignore polymerisation of the two principal monomers in
the aqueous phase, and of the carboxylic acid. The advantages and disadvan
tages of several different types of on-line sensors for use in industrial s
ituations are also reviewed.