Modeling of Polyamide 66 Solid StatePolymerization: Drawing a Chemical ReactionScheme

摘要

A chemical reaction scheme is proposed here to describe the polyamide 66 (PA 66) solid state polymerization (SSP) with effective kinetic parameters. The main objective of the suggested model is to predict the maximum molecular weight attainable at each SSP isotherm, which is in turn determined by the occurrence of polymer chain degradation coupled to other important side reactions. Accordingly, a number of side reactions have been firstly considered, based on which a comprehensive particle model was constructed to predict PA 66 kinetics, equilibrium, and transport phenomena. The SSP model parameters were estimated with a maximum-likelihood estimator, using data measured under kineticand diffusion-controlled process conditions for reaction temperatures in the range of 160–200 8C and reaction times up to 8 h. Calibration models were also developed to allow the determination of PA 66 solution viscosities. 1. Introduction