KINETICS OF COMPETITIVE POLYMERIZATION IN BIDISPERSE SEED SYSTEMS USING OIL-SOLUBLE INITIATORS - CALCULATION OF EFFECT OF VARIOUS DIMENSIONLESS PARAMETERS

Expressions for calculating the stationary state distribution of radic als in a bidisperse seed system initiated by oil-soluble initiators we re developed. Dimensionless parameters were used throughout, thus maki ng it possible to obtain general trends without introducing specific n umerical values. Desorption and reabsorption of radicals, aqueous phas e termination, partition of the initiator into the aqueous phase, and a possible generation of single radicals are taken into account. The r adical entry and exit rate coefficients are formulated in terms of pow er laws with respect to particle diameter. No discrimination of the va rious radical species and their origin is made. The derivation is base d on a probabilistic stationary state analysis leading to third-order recurrence relations that are solved using confluent, hypergeometric K ummer functions. A selection of curves illustrating the effect of vari ous dimensionless parameters on the calculated average number of radic als per particle, the order of volume growth with respect to the parti cle diameter, and relative rates are given. (C) 1995 John Wiley & Sons , Inc.