Off-lattice Monte Carlo simulation of hyperbranched polymers, 1 Polycondensation of AB2 type monomers

Step Polymerization

“…The number of unreacted B groups increases with increasing X n and f . A hyperbranched polymer is often characterized by the degree of branching DB [Holter et al, 1997;Jo and Lee, 2001;Kim, 1998;Lee et al, 2000]. For the hyperbranched polymer produced from AB 2 , there are three different types of repeat units: dendritic, linear, and terminal units defined as units having two, one, and no B groups reacted, respectively.…”

Off-Lattice Monte Carlo Simulation of Hyperbranched Polymers, 2. Effect of the Reactivity Ratio of Linear to Terminal Unit on the Microstructure of Hyperbranched Polymers Based on AB2 Monomers

“…By dividing Equation (6) by Equation (5) and then integrating the obtained equation, Hölter et al [7] derived an expression for the dependence of conversion on T (Equation (8)). For the case of x = 2, Equation (11) and (12) can be used instead of Equation (8) and (9), respectively, because Equation (8) and (9) do not have a solution at x = 2. Consequently D is estimated simply from Equation (10).…”

“…[6,7] Recently, Kim [10] has proposed the Wiener index as a more discriminating structural index because the DB has a limitation that hyperbranched molecules with significantly different topologies may have the same DB. In our previous report, [9] we simulated the polycondensation of hyperbranched polymers, based on AB 2 monomers, by using an off-lattice Monte Carlo method in order to investigate the polymerization kinetics and their microstructures, where the reactivities of linear units and terminal units are assumed to be the same. [11,12] Computer simulations may provide valuable insights into the microstructure of hyperbranched polymers.…”

Reaction kinetics of nonideal hyperbranched polymerizations: Influences of chain rigidity and reaction reversibility

“…However, the steric factors and intramolecular cyclization are hardly considered in theoretical models. In comparison, the simulation methods,10, 20, 24, 32 which combine the effects of steric factors, diffusion of monomers, and relaxation of polymer chains, can be used to study the hyperbranched polymerizations in more realistic conditions. For instance, in the simulations of self‐condensing vinyl polymerizations (SCVPs) of AB* type monomers and AB n ( n = 2, 4) type polymerizations via reactive bond fluctuation lattice model,10, 20 we found that the maximal number‐average degree of polymerization, P n , and polydispersity index, PI, are about 50 and 4.0, respectively, by tuning the monomer concentration and substitution effect.…”

“…In former studies of step growth hyperbranched polymerizations (e.g., AB 2 type polycondensation), only irreversible reactions were studied extensively via various models 1, 7, 10, 11, 24, 28, 29, 32, 43. However, the reversible reactions also take place in some systems, for example, the polyesterification and polyamidation reactions.…”