Abstract: In this paper, the unsteady state kinetic problems of initiated free-radical polymerisation are studied by means of Monte Carlo simulation method. The peculiar "None Stretching Problem", which is accompanied with the numerical solution of the kinetic equation of free-radical polymerization, was solved by using the biased sampling method in the Monte Carlo simulation. The results of Monte Carlo simulation are in agreement with those of analytical solution of the unsteady state kinetic equation. Because of the simple character of Monte Carlo algorithm, the Monte Carlo method can be easily extended to treat the system of free-radical polymerization with a higher complexity.

Key words: Free radical polymerization, Monte Carlo simulation method, Biased sampling method