Solid‐state polycondensation of poly(ethylene terephthalate): Kinetics and mechanism

Abstract A numerical method to seek a solution for the solid‐state polycondensation (SSP) proces has been proposed to analyze the mechanism of SSP. Results expound that, for the industrial SSP process of PET, the overall reaction rate in a single pellet is appropriately simulated by the diffusion and reaction rate jointly controlling the model. From the core to the surface the SSP rate increase monotonically due to a gradual reduction of the concentration of such by‐products as ethylene glycol and water. However, the SSP rate at any location within the pellet is constrained between two purely reaction rate controlling cases. © 1995 John Wiley & Sons, Inc.