The effect of temperature and humidity on the long‐term performance of poly(butylene terephthalate) compounds

Abstract

Abstract A model was developed that closely fits new and previously published test data for the aging of poly(1,4‐butylene terephthalate) (PBT) compounds under conditions of elevated temperature and high relative humidity. The model equation, stated in terms of absolute temperature and water vapor partial pressure, allows extrapolation of accelerated aging data to ambient conditions that prevail in realistic applications of the materials. For practical reasons, the water vapor partial pressure is preferred as a model variable over relative humidity, although it is shown that both variables are equivalent in a formal sense.