Abstract:

Non-isothermal degradation properties of polyethylene terephthalate and polybutylene terephthalate were studied and compared by multiple linear regressions (MLR). Kinetic parameters, such as activation energy Ea, pre-exponential factor Z and reaction order n, were calculated by kinetic analysis software. And on this basis, relations between the extent of conversion, temperature and time of polyethylene terephthalate and polybutylene terephthalate were predicted. The results show that polyethylene terephthalate exhibits good thermal stability, which initial degradation temperature is higher than polybutylene terephthalate at the same heating rate. However, its rate in thermal decomposition is faster. All of those are related with the chain structure and the oligomers produced in thermal degradation.