Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
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.
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