Automatic polymerization reactor with on‐line data measurement and reactor control

An automatic polymerization reactor has been developed for on‐line measurement of conversion, viscosity, and molecular weight distribution of homogeneous free radical polymerization. For on‐line measurements during polymerization a fraction of the reaction mixture is pumped as bypass through a densimeter and a viscometer. In time intervals of 15 min samples are taken, diluted semi‐automatically, and then injected into a high performance gel permeation chromatography for determination of the molecular weight distribution of the polymers. A microcomputer collects these data, calculates the conversion of reaction and the output data for different control units. Methyl methacrylate is polymerized batch‐wise in solution with ethyl acetate as solvent and dicyclohexyl peroxydicarbonate as initiator. Semi‐batch polymerizations with constant reaction rate are performed by feeding initiator which is controlled by open‐loop and closed‐loop control.