MODELING OF SOLID-STATE POLYMERIZATION OF POLY(ETHYLENE-TEREPHTHALATE)

A mathematical model for solid-state polymerization of poly(ethylene t erephthalate) was developed. The effects of temperature and chain enta nglement on chain mobility were considered to estimate the rate consta nts of chemical reactions. The diffusivities of volatile byproducts co uld be determined using the free volume theory.(13,14) The model predi ctions were validated with experimental data reported in the literatur e. In addition, assuming that the concentration profiles of volatile b yproducts in spherical particles are described by a sinusoidal functio n, the mass transfer rate of the byproducts at a given time could be d erived as an ordinary differential equation that can be easily treated . (C) 1998 John Wiley & Sons, Inc.