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

Abstract

To deeply understand the dependence of hyperbranched polymerization on the specialties of molecular chain and chemical reaction, the reaction kinetics of nonideal hyperbranched polymerizations considering the chain rigidity and reaction reversibility are studied using the reactive three‐dimensional bond fluctuation lattice model. It is found that, with the increase of chain rigidity, the formation probability of intramolecular rings decreases and less intramolecular rings with larger size are formed. It results in the increase of the degrees of polymerization and polydispersity index with the rise of chain rigidity at higher conversion. Furthermore, our simulation shows that the reversibility of reaction has strong influences on the equilibrium state and kinetic process of hyperbranched polymerizations. When the ratio of reverse reaction probability to forward reaction probability is larger, the conversion and degrees of polymerization quickly grow to the equilibrium value simultaneously. At smaller reverse reaction probability, however, the weigh‐average degree of polymerization and polydispersity index further increase slowly after approaching the equilibrium conversion. Our results are well‐consistent with the experiments to indicate that the introduction of the specialties of macromolecule and chemical reaction are necessary for quantitative analysis of the realistic hyperbranched polymerizations. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

A coarse-grained molecular dynamics – reactive Monte Carlo approach to simulate hyperbranched polycondensation

“…Most previous efforts were focused on the generic properties of hyperbranched polymerizations. These approaches covered the inuence of substitutions, 9,12,[18][19][20][21] the addition of core molecules, 11,[22][23][24][25] intramolecular ring units, 14,17,26,27 the monomer concentration, 17,21,28 and the chain rigidity as well as the reaction reversibility 29 on the molecular weight distribution and degree of branching. To our knowledge, investigations of specic hyperbranched polymerizations using a molecular model with structural details have been reported neither in theoretical nor in simulation studies.…”