| The effects of chemical conversion and isothermal physical aging on the properties of crosslinking thermosetting systems (e.g., epoxy/amine) and linear thermosetting systems (e.g., polyimide) are investigated. The decreasing density in the glassy state of a thermosetting system with increasing conversion is termed "anomalous". The objective is to systematically describe the so-called anomalous behavior and to identify the molecular origins of such behavior. The main results follow. (1) A simple entropic model of the glass transition temperature (T... |
