Energetic materials such as explosives, propellants, and pyrotechnics are difficult and dangerous to process because of their instability and the potential for violent reactions. Simpson et al used a sol-gel method to cast these materials to near-net shape or form homogeneous molding powders. Reactive monomers are dissolved to form a solution and polymerized to form a highly crosslinked three-dimensional gel. The composition, porosity, particle sizes, gel time, surface areas, and density can be tailored and controlled by the solution chemistry. The gel is dried to produce a highly porous low-density aerogel or by controlled slow evaporation to produce a xerogel. Applying stress during the extraction phase can result in high-density materials.
Roger D. Corneliussen is Professor Emeritus of Materials Engineering, Drexel University in Philadelphia, Pennsylvania, USA. He is editor of Maro Polymer Alerts and the Maro Polymer website (www.maropolymeronline.com). He has been active in SPE since 1962 and has served on the Board of the Philadelphia Section and as SPE Councilor. For Maro Patent Alerts, he reviews all U.S. Patents weekly, makes links to the polymer-related patents, and sends the links daily to subscribers. These patent abstracts are based on the weekly selection process. To sample Maro Patent Alerts, email a request to firstname.lastname@example.org.
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|Title Annotation:||industry PATENTS|
|Article Type:||Brief article|
|Date:||Mar 1, 2012|
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