Interpretation of molecular structure and kinetics in melt condensation of A₂ oligomers, B₃ monomers, and monofunctional reagents

This article applies kinetic Monte Carlo simulations to interpret experimental measurements in the polymerization of hyperbranched poly(ether esters)s in a melt condensation of A₂ oligomers and B₃ monomers. Building on the analytical modeling of Flory and Stockmayer, additional effects of cycle formation, unequal reactivities, and end-capping reagents are added into the simulations to describe A₂ + B ₃ polymerization in the absence of a solvent. The experimental data have been published separately,¹ and here it is compared to the model predictions in order to quantitatively assess whether the data are consistent with these models. On the basis of the modeling, we conclude that cycle formation is negligible, suppression of the third B group is insignificant, and the mobility of the free B₃ monomer leads to enhancement of its reaction rate. The addition of the monofunctional end-capping reagents does not necessarily lead to suppression of branching in the A₂ + B ₃ system and depends sensitively on the stoichiometry of the reactants.