Ehp. Wolff et Anr. Bos, MODELING OF POLYMER MOLECULAR-WEIGHT DISTRIBUTIONS IN FREE-RADICAL POLYMERIZATION REACTIONS - APPLICATION TO THE CASE OF POLYSTYRENE, Industrial & engineering chemistry research, 36(4), 1997, pp. 1163-1170
A computational model for free-radical polymerization reactions in an
ideally macromixed batch stirred tank reactor has been developed. The
polymerization process may take place using an initiator, a chain-tran
sfer agent, and a prescribed temperature program. The model yields, as
a function of time, the monomer conversion, the number- and weight-av
erage molecular weights, and a complete molecular weight distribution
(MWD) of both the growing and dead polymer chains. A kinetic scheme ty
pical for free-radical polymerization and the method to generate a com
plete MWD have been adopted from the literature. We included a fundame
ntal approach to account for the ''viscosity effects'' such as the cag
e effect, gel effect (Trommsdorff-Norrish-Smith effect), and glass eff
ect as proposed by Achilias and Kiparissides. An expression to account
for the chain transfer to a solvent or to a chain-transfer agent has
been added. The model has been successfully verified with two literatu
re cases and demonstrated with two of our own defined cases.