Advanced Materials & Processes

FEB 2015

Covers developments in engineering materials selection, processing, fabrication, testing/characterization, materials engineering trends, and emerging technologies, industrial and consumer applications, as well as business and management trends

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METAL-FREE CATALYST PROCESS USES LIGHT FOR RAPID POLYMERIZATION Materials science researchers from University of California, Santa Barbara, and The Dow Chemical Co., Midland, Mich., created a novel way to overcome a major hurdle preventing widespread use of controlled radical polymerization. In a global polymer industry valued at hundreds of billions of dollars, a technique called atom transfer radical polymerization (ATRP) is emerging as a key process for cre- ating well-defined polymers for a vast range of materials, from adhesives to electronics. However, current ATRP methods use metal catalysts, a major roadblock for applications in which metal contam- ination is an issue, such as materials used for biomedical purposes. The new method does not involve heavy metal catalysts like copper. Instead, an organic-based photocatalyst—and light— serve as the stimulus for the reaction. "We looked toward developing an organic catalyst that is highly reduc- ing in the excited state, and we found it in an easily prepared catalyst, phe- nothiazine," explains Craig Hawker, director of the Dow Materials Institute at UCSB. ATRP is already used widely across dozens of major industries, but the new metal-free rapid polymeriza- tion process enables controlled radical polymerization to be used in new appli- cations. "Many processes in use today start with ATRP. This method opens doors for a new class of organic-based photoredox catalysts. The develop- ment of living radical processes, such as ATRP, is arguably one of the biggest things to happen in polymer chemistry in the past few decades," adds Hawker. AUTO SHOw FEATURES 3D-PRINTED MUSCLE CAR The Department of Energy's Oak Ridge National Laboratory (ORNL), Tenn., highlighted its additive manufacturing research at the 2015 North American In- ternational Auto Show held in January in Detroit by showcasing a 3D-printed Shelby Cobra. The car was printed at DOE's Manufacturing Demonstration Fa- cility at ORNL using the big area additive manufacturing (BAAM) machine, which can manufacture strong, lightweight composite parts in sizes greater than one cubic meter. The 1400-lb vehicle con- tains 500 lb of printed parts made of 20% carbon fiber. It took six weeks to design, manufacture, and assemble the Shel- by, including 24 hours of print time. The new BAAM system, jointly developed by ORNL and Cincinnati Inc., can print com- ponents 500 to 1000 times faster than to- day's industrial additive machines. ORNL researchers say the speed of next-gener- ation additive manufacturing offers new opportunities for the automotive indus- try, especially in prototyping vehicles. PROCESS TECHNOLOGY A metal-free atom transfer radical polymerization process uses an organic-based photocatalyst. Courtesy of Peter Allen, UCSB. BRIEFS Alcoa, New York, will invest $190 million in its Davenport Works, Iowa, facility to expand aerospace and industrial products. Technology to enhance performance of thick aluminum and aluminum-lithium plate in various applications, including wing ribs and fuselage frames, will be installed. The investment also includes a very thick plate stretcher for reducing stress introduced into plate during manufacturing. Company sources say the upgrades will enable production of the largest high-strength monolithic wing ribs in the industry. 3D-printed Shelby Cobra. Courtesy of ORNL. A D V A N C E D M A T E R I A L S & P R O C E S S E S | F E B R U A R Y 2 0 1 5 1 2

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