Kinetic model of hyperbranched polymers formed by the polymerization of AB2 monomer with a substitution effect

Hyperbranched polymers obtained by the polymerization of AB(2)-type monomer with a substitution effect on the B-2 groups were studied by means of the kinetic model. In this polymerization with the substitution effect, if one of the B-2 group reacts first, the reactivity of the remaining unreacted B group will be changed. The profiles of the degree of polymerization, polydispersity, degree of branching, and structural units of the hyperbranched polymers with the conversions were all calculated by the generating function method. It is shown that the weight-average degree of polymerization and the degree of branching of the hyperbranched polymers having substitution effect differ from that with equal reactivity of the B-2 groups. If the substitution effect causes an increase in the rate constant after one of the B-2 groups has reacted, a broader molecular weight distribution and a higher degree of branching are observed. (C) 2002 Elsevier Science Ltd. All rights reserved.