In this work, the effect of operational conditions on the performance of a controlled batch polymerization reactor was investigated experimentally. The effect of agitation speed on conversion and heat transfer coefficient in free radical chain growth polymerization in this controlled, stirred, jacketed batch reactor was also investigated. The transient response of the polymerization reactor following sequential step changes in agitation speed has been obtained experimentally. The experiments were conducted under optimal loading conditions calculated by using Lagrange's multiplier method. The reactor temperature was controlled by manipulating the heat input to the reactor. Some correlations are also provided relating the viscosity and the overall heat transfer coefficient to the monomer conversion. (C) 2002 Elsevier Science B.V. All rights reserved.