Influence of polymerization procedure on polymer topology and other structural properties in highly branched polymers obtained by A2+B3 approach

Computational studies were carried out to investigate the influence of polymerization procedure on the topology and various macromolecular characteristics of the highly branched polymers formed by the reaction of A(2) and B-3 type monomers through step-growth polymerization reactions. The influence of three different polymerization procedures on the properties of the polymers formed was investigated, namely, (i) slow addition of A(2) over B-3, (ii) slow addition of B-3 over A(2), and (iii) mixed A(2) + B-3. Topology, degree of branching, number and weight average molecular weights, and polydispersity index of the polymers were determined using Monte Carlo simulations, assuming different levels of cyclization ratios during the reactions. Interestingly model polymers obtained by the slow addition of B-3 over A(2) produced much higher degree of branching or truly hyperbranched polymers, when compared with the other two methods, which mainly resulted in linear growth with slight branching. (C) 2008 Elsevier Ltd. All rights reserved.