Some practical aspects of designing a laboratory scale batch polymerization reactor without gas entrapment and interfaced with virtual instrumentation

A 1-l stainless steel (SS) reactor with a glass bottom has been designed with symmetrically placed internals so that gas entrapment is completely avoided during bulk polymerization of methyl methacrylate (MMA). This reactor is instrumented and controlled using virtual instrumentation. The power consumed by a constant-speed stirrer motor is measured as a function of time which, along with the temperature history, can be used to infer the state (monomer conversion xm and weight average molecular weight Mw) of the viscous reaction mass. This study highlights the importance of symmetry in the design of the reactor, proposes a novel reactor design, and discusses in detail the temperature control configuration that can help track any temperature history. Some preliminary results are reported for bulk polymerization of MMA and a correlation developed for the stirrer power, which can be used for soft sensing.