MOLECULAR SIMULATION OF POLYMERIC MATERIALS Sandia National Laboratories has developed a system for predicting mechanical, transport, and interfacial properties of polymers from a knowledge of the molecular architecture of the monomers using proprietary molecular simulation codes, involving up to 1 million atoms, run on SNL massively parallel computers. Important applications include: molecular design of high-barrier films, polymer membranes for gas separations, and more durable aging-resistant rubbers. Prediction of strength properties of polymer materials and polymer surfaces, gas diffusion rates through barrier films, and rate of strength loss due to oxidation. Potential Benefits We have the ability to do molecular simulation with up to 1 million atoms results in more reliable predictability of polymer properties compared to the 100,000 or less atoms used in competitive modeling systems. The unique massively parallel computers at Sandia enable calculations at this order of magnitude. Ability to directly observe the impact of molecular architecture on macroscopic properties of polymers identifies cause-and-effect relationship between chemical structure and final properties as well as creates critical benchmarks for performance attributes. Ability to perform low-cost "what-if" computer experiments to screen candidates for enhanced performance products. Demonstrated Achievements We have successfully predicted the diffusion of oxygen in polyisobutylene, ethylene-propylene rubber, polyethylene, and polypropylene. We have generated realistic cross-linked polymer structures containing over 1 million atoms, exceeding 0.01 microns in size. Simulated gradient-driven flux rate of penetrant molecules through polymer membranes. References The polymer simulation capability at Sandia is part of a $3 million research program in polymer degradation. This program supports work in a variety of disciplines, including experimental studies and engineering models. Sandia scientists working in this field have extensive experience in materials modeling on the atomic scale. Sandia has issued 16 publications and has participated in numerous conferences including several "invited seminars". This proprietary Sandia capability may be applied to solve challenging problems in the field of polymer and other organic sciences. Sandia has the flexibility to form specific teams of technical experts from any or all of the above capabilities to focus expertise on specific technical challenges. We are interested in making this technology available to companies responsive to partnering with Sandia to develop near/term and/or future applications via licensing or cooperative development agreements. For further information, please respond by mail or fax to Joanne Trujillo no later than December 3, 1998 at: Sandia National Laboratories, MS 1380, P. O. Box 5800, Albuquerque, New Mexico 87185-1380. Fax: (505) 843-4163. Please indicate the date and title of this CBD notice. E-MAIL: Joanne Trujillo, jmtruji@sandia.gov. Posted 11/19/98 (W-SN273121).

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