In this study, it is presented for the first time, the characterization of an amorphous polyamide after having been subjected to humid thermal conditions such as those typically applied in the industrial sterilization of packaged foods. From a fundamental point of view, it was fortuitously found that the combination of heat and moisture, with and without the assistance of pressure, was capable of inducing some crystallization in the otherwise amorphous polymer. Characterization of the crystallization process was carried out by differential scanning calorimetry, Fourier transform infrared, and simultaneous time-resolved small and wide angle X-ray scattering synchrotron experiments. The crystallization of the polymer began as characterized by wide angle X-ray scattering and differential scanning calorimetry in the presence of humidity at similar to 90 degrees C and extended up to 120 degrees C under autoclave conditions, and it is thought to be the result of heated moisture being able to disrupt the intense amide groups self-association. Thus, the thermally activated molecular structure is thought to become plasticized by the combined presence of heat and water which, in turn, provoke sufficient segmental molecular mobility in the system to promote some degree of lateral order. Propertywise, the resulting consequences of this behavior are an increase in the barrier properties to oxygen and a reduction in water sorption. From an applied view point, it is suggested that this unexpected behavior could make this polymer of significant interest in retortable food packaging applications. (c) 2006 Wiley Periodicals, Inc.