General kinetic model of imperfect living polymerization (IV) - Non-steadystate analysis for reaction systems with two active species

The living ionic polymerization with two active species was theoretically s tudied, presenting the expressions of the number- and weight-average degree s of polymerization and the polydispersity index. The numerical calculation shows that both steady state and non-steady state approaches result in the essentially same outcomes when the exchange rate between the two active sp ecies Is larger than the rates of chain propagation; however, the steady st ate method leads to a larger error and only the non-steady state approach i s valid if the exchange rate between the two active species is comparable t o or smaller than propagation rates. In addition, the molecular weight dist ribution of the resulting polymer becomes narrower with the value of k(p) a pproaching to k'(p) and with increasing M-0/I-0.