MONTE-CARLO SIMULATION OF CHAIN-LENGTH DISTRIBUTION IN RADICAL POLYMERIZATION WITH TRANSFER-REACTION

In this paper, the basic principle and a Monte Carlo method are described for numerically simulating the chain-length distribution in radical polymerization with transfer reaction to monomer. The agreement between the simulated and analytical results shows that our algorithm is suitable for systems with transfer reaction. With the simulation algorithm, we confirm that transfer reaction has a similar effect as disproportionation on the molecular weight distribution in radical polymerization with continuous initiation. In the pulsed laser (PL) initiated radical polymerization with transfer reaction, the 'waves' on the chain-length distribution profile become weaker as the ratio of transfer reaction rate constant, k(tr), to the propagation rate constant, k(p), is increased in the case with either combination-type or disproportionation-type termination. Moreover, it seems that the combination termination has a broadening effect on the waves. Therefore, k(p) can also be determined by precisely locating the inflection point L(0) on the chain-length distribution profile for radical polymerization with transfer reaction, unless k(tr) is large enough to smear out the waves on the chain-length distribution.