6533b7d3fe1ef96bd126091c

RESEARCH PRODUCT

Kinetic Analysis of “Living” Polymerization Processes Exhibiting Slow Equilibria. 5. Effect of Monomer Transfer in Cationic Polymerization and Similar Living Processes

subject

description

This work deals with the kinetics of polymerization processes with chain transfer to monomer and reversible formation of dormant species. Such a mechanism is typical for cationic polymerization in the presence of Lewis acids as co-initiators. The expressions of number- and weight-average degrees of polymerization and polydispersity index are derived rigorously for a mechanism with free ions as the active species, but it is also applied to other mechanisms, e.g., ion pairs as active species. Plots of polydispersity index versus monomer conversion can be easily computed on a PC computer even though the expressions for the weight-average degree of polymerization and the concentration of residual initiator consist of confluent hypergeometric functions. Numerical calculations show that the polydispersity index of the resulting polymer approaches Mw/Mn = 2 with increasing rate constant of chain transfer. Addition of common ions led to narrower molecular weight distributions. For the polymerization of indene wit...