Kinetic Model of Hyperbranched Polymers Formed by Self-Condensing Vinyl or Self-Condensing Ring-Opening Polymerization of AB Monomers Activated by Stimuli with Different Reactivities

Hyperbranched polymers (HBPs) formed by the self-condensing vinyl polymerization (SCVP) or self-condensing ring-opening polymerization (SCROP) of monomer AB activated by stimuli with various reactivities were investigated by the generating function method. Two different cases were discussed: in case I, the concentration of the stimulus decayed during the activating reaction, and in case II, the stimulus acted as a catalyst to activate the monomer AB, and the change in stimulus concentration was neglected. The reduced number- and weight-average degree of polymerization (DP* n and DP*w,) and degree of branching (DB) of the HBPs were found to depend not only on the mole ratio of stimulus to monomer AB (λ) but also on the reactivity ratio of the stimulus (β). The DP* n , DP* n and polydispersity index of the reduced degree of polymerization increased with decreasing reactivity of the stimulus. In case II, when λβ > 1, there were only a few influences on the average degree of polymerization by λβ, and the results were similar to those of case I. However, when λβ<1, the degree of polymerization differed significantly between the two cases. The maximum degree of branching of about 0.5 was obtained with near full conversion of A, and the degree of branching depended on the amount and reactivity ratio of the stimulus.