Simulation of ARB type reversible step growth polymerization in semibatch reactors

The polymerization of ARB type reversible step growth polymerization in semibatch reactors has been simulated. It is assumed that the condensation byproduct W and the monomer P₁ both can vaporize, but P₁ is refluxed back to the reactor. Raoults law as well as Flory–Huggins theory have been used to account for vapor–liquid equilibrium. The degree of polymerization, μ_n, and the polydispersity index D_N have been computed for various situations. The results are found to be most sensitive to the total pressure and the equilibrium constant. A limiting total pressure history P_T(T) has been obtained, going below which does not help to increase μ_n. The final set of equations incorporate both equalities as well as inequalities, and a simple and efficient computational scheme has been suggested to solve them.