Accelerated aging characteristics of polyesters in different environs

An attempt is made to determine the effects of the aging environment on the performance of polyester engineering thermoplastics, and to determine if a simplified aging model can be used to determine the long-term performance characteristics. Initial results on PET and PBT materials indicate that life can be predicted from the data generated through a short-time thermal analysis test method. Long-term life in transformer applications, can be estimated from the data generated by thermal analysis by applying the applicable percent conversion aging line to the thermal cycle data or the long-term compatibility data. From the testing completed thus far, it has been demonstrated that severe thermal aging occurs under elevated temperature, in air. The effects of a transformer oil environment, tend to reduce the oxidation effects, and thermal cycling of the temperature positively reduces the thermal effect