We report on modeling of free-radical polymerization of styrene in a stirred tank reactor spinning disc reactor (STR-SDR) arrangement using Kinetic Monte Carlo (KMC) simulation algorithm. The prepolymer from batch reactor was transferred to SDR and simulation results were validated comparing conversion and molecular weight of the generated molecules in the batch reactor and SDR with corresponding values from experimental data. The developed model was also applied to simulate SDR under a range of different operating conditions to accurately predict the resulting polymer properties. In this way, different prepolymer conversions were theoretically adapted to probe the evolution in chain microstructure until polymerization terminated on the rotating disc. The developed computer code based on KMC approach enables precise monitoring of molecular-level events in the reactor like variations in molar concentration of macroradicals and molecular weight distribution with time, and provides a greater insight into the STR SDR cascade polymerization of styrene monomer. (C) 2014 Elsevier B.V. All rights reserved.