Estimation of Kinetic Parameters and Mathematic Model Validation for Nylon-6 Process

Abstract This work presents the simulation of the hydrolytic polymerization process of nylon-6 in a lab-scale semi-batch reactor, using e-caprolactam as monomer and acetic acid as monofunctional acid chain terminator. The kinetic scheme comprises 6 reactions: 3 main reactions, 2 side reactions associated with the cyclic dimer formation and one monofunctional acid termination. Operating conditions were obtained from previous definitions and kinetic parameters were estimated from experimental data. The proposed optimization problem to estimate the kinetic parameters was solved by the Successive Quadratic Programming (SQP), a deterministic method. It was shown that the method is able to determine the final solution with good precision. The validity of the model was confirmed by comparison of the results obtained by computer simulation using the software Aspen Polymer Plus ® and the process real data.