Simulation of molecular weight distribution and cyclic oligomer formation in the polymerization of nylon 6

The reversible polymerization of nylon 6 including ring opening, polycondensation, polyaddition, and cyclization reactions as well as the reaction with monofunctional acids was simulated for an isothermal batch reactor at 235°C. The cyclic oligomer concentrations, the molecular weight distributions, and its moments have been computed using a chain length-dependent equilibrium constant for the cyclization reaction. Even though the cyclization step does not influence the monomer conversion considerably, it does effect the molecular weight distribution and its moments