Development of a methodology to predict material properties from environmental exposure. I. Kinetic treatment

This study focuses on bisphenol A polycarbonate and tracks changes in the properties of this material as a function of the degree of degradation, τ, induced by a hostile environment. Among many possible environmental effects, we have limited this investigation to those associated with elevated temperature, although the methodology is general. This τ parameter is a product of the kinetic rate constant, k, found from isothermal kinetics, and the time of degradation, t. The elucidation of τ has been linked to the measurement of the molecular weight distribution, which, in turn, can be related to various properties to yield valuable predictive relationships. Only the thermal history of the polymer and its initial properties are required for the model. This technique is not limited to a specific polymer or even to thermal degradation. As long as the kinetics of the process can be mathematically modeled, this approach should apply to a host of other situations, providing property prediction simply from knowledge of the material history. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 794–801, 2002