Kinetics of thermal degradation of liquid-crystalline aromatic polymers

The kinetics of thermal degradation of thermotropic Liquid-crystalline aromatic polymers under nitrogen and air was systematically investigated by dynamic thermogravimetry. The thermal degradation temperature and kinetic parameters such as activation energy, decomposition order and frequency factor, have been determined by three methods on the basis of a single heating rate measurement. The effect of polymer molecular structure, end group, testing atmosphere and calculating method on the characteristic temperatures, kinetic parameters, and lifetime have been discussed. The initial decomposition temperature and estimated Lifetime for the most thermotropic aromatic polymers are above 420 degrees C and larger than 26 days at 200 degrees C or 2.3 hours at 300 degrees C, respectively. Some theoretical explanations of variation of thermal and kinetic parameters have been proposed.