With time, long chain polymers degrade into shorter chain length molecules. As this happens, the material properties of the polymer also change. This project seeks to better characterize the degradation with time of polymeric binders used in high explosives.
Estane 5703, a polyesterurethane used in the binder of the Plastic Bonded Explosive PBX 9501, slowly degrades. This project aims to predict its molecular weight distribution and chemical composition as a function of time to times much longer than the ages of any available samples. For a simple but somewhat outdated introduction to the problem, you can see the short article (in pdf format), "Chemical Mechanisms and Kinetics of Estane Aging," which is part of LANL Report LA-UR-97-1559.
For the first preliminary preditions, you can see LANL Report LA- UR-98-6014 (in pdf format), "Chemical Kinetics of the Aging of Estane 5703 in PBX 9501. I. First Preliminary Predictions," and its two figures, "Figure 1" and "Figure 2."
People in T-12 working on this project include: