Monofunctional initiators are extensively utilized in free radical polymerization. In order to enhance productivity, usually higher temperature is used, however this leads to lower molecular weights. Bifunctional initiators increase the polymerization rate without decreasing the average molecular weight and this can be desirable. Bifunctional initiator is an important issue to be investigated and it is of great interest to industries. The objective of this work was to develop comprehensive mathematical models to simulate polymerization reactors with mono- and bi-functional initiators, using monomers that will produce linear and branched polymers. Polystyrene as linear polymer and poly(vinyl acetate) as branched polymer were considered. Models prediction showed good agreements with experimental data from literature and brought new information about vinyl acetate polymerization using bifunctional initiator. © 2005 Elsevier B.V. All rights reserved.20C445450Benbachir, M., Benjelloun, D., Investigation Of Free Radical Polymerization Using Diperoxyesters As Bifunctional Initiators (2001) Polymer, 42, pp. 7727-7738Dhib, R., Gao, J., Penlidis, A., Simulation Of Free Radical Bulk/Solution Homopolymerization Using Mono-and Bifunctional Initiators (2000) Pol. Reac. Eng., 8 (4), pp. 299-464Gao, J., Penlidis, A., (1996) J. Macrom. Sci.-Revs. Macrom. Chem. Phys., C, 36, pp. 199-404Machado, P.F.M.P.B., Free Radical Polymerization of Linear and Branched Polymers using Mono and Bifunctional Initiators (2004) MSc Thesis, , State University of Campinas