Computational scheme for the calculation of molecular weight distributions for nylon 6 polymerization in homogeneous, continuous-flow stirred-tank reactors with continuous removal of water

An efficient computational scheme has been established for obtaining the molecular-weight distributions (MWDs) for Nylon 6 polymerization in homogeneous, continuous-flow stirred-tank reactors (HCSTRs) with water vaporization. A three-step procedure is used: the moment equations are solved by a sequential application of Brown's algorithm, the moments so calculated are used to give an empirical Flory-Schultz distribution and, finally, this empirical distribution is used as a starting guess in Brown's algorithm applied to species mass-balance equations to give the exact MWD. The moment-closure approximations normally used for hutch reactors have been found to work equally well with HCSTRs for residence times of industrial significance