Kinetics of reversible polymerization

This paper extends the kinetic theory of irreversible polymerization (Smoluchowski's equation) by including fragmentation effects in such a way, that the most probable (equilibrium) size distribution from the classical polymerization theories is contained in our theory as the stationary distribution. The time-dependent cluster size distributionc_k(a(t)) in Flory's polymerization modelsRA_f andA_fRB_g, expressed in terms of the extent of reaction, has the same canonical form as in equilibrium, and the time dependence of(t) is determined from a macroscopic rate equation. We show that a gelation transition may or may not occur, depending on the value of the fragmentation strength, and, in case a phase transition takes place, we give Flory- and Stockmayer-type postgel distributions.Inspec numbers: 0550, 6460, 8235, 6475.