For a batch emulsion polymerization of isoprene at 10 degrees C in the presence of a chain transfer agent, a previous mathematical model (Minari et al., J. Appl. Polym. Sci. 2010, 116, 590) was extended for predicting the molecular weight distributions of all the generated long chain branched topologies; with each topology characterized by the number of tri- and tetra-functional branches per molecule. According to the new model predictions, at the reaction end the linear topology remains as the most abundant (with similar to 40% of the total mass), followed by the single trifunctionally branched topology (with similar to 20% of the total mass). The model can be used for developing strategies for controlling the distribution of branches/molecule, for estimating melt viscosities, etc. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013