Composite Properties of RTM370 Polyimide Fabricated by Vacuum Assisted Resin Transfer Molding (VARTM)

RTM370 imide resin based on 2,3,3?,4?-biphenyl dianhydride (a-BPDA), 3,4'-oxydianinline (3,4'-ODA) with the 4-phenylethynylphthalic (PEPA) endcap has been shown to exhibit a high cured T(sub g) (370 C) and low melt viscosity (10-30 poise) at 280 C with a pot-life of 1-2 h. Previously, RTM370 resin has been successfully fabricated into composites reinforced with T650-35 carbon fabrics by resin transfer molding (RTM). RTM370 composites exhibit excellent mechanical properties up to 327?C (620?F), and outstanding property retention after aging at 288?C (550?F) for 1000 h. In this work, RTM370 composites were fabricated by vacuum assisted resin transfer molding (VARTM), using vacuum bags on a steel plate. The mechanical properties of RTM370 composites fabricated by VARTM are compared to those prepared by RTM

Tailoring Elastic Properties of Silica Aerogels Cross-Linked with Polystyrene

The effect of incorporating an organic linking group, 1,6-bis(trimethoxysilyl)hexane (BTMSH), into the underlying silica structure of a styrene cross-linked silica aerogel is examined. Vinyltrimethoxysilane (VTMS) is used to provide a reactive site on the silica backbone for styrene polymerization. Replacement of up to 88 mol 1 of the silicon from tetramethoxyorthosilicate with silicon derived from BTMSH and VTMS during the making of silica gels improves the elastic behavior in some formulations of the crosslinked aerogels, as evidenced by measurement of the recovered length after compression of samples to 251 strain. This is especially true for some higher density formulations, which recover nearly 100% of their length after compression to 251 strain twice. The compressive modulus of the more elastic monoliths ranged from 0.2 to 3 MPa. Although some of these monoliths had greatly reduced surface areas, changing the solvent used to produce the gels from methanol to ethanol increased the surface area in one instance from 6 to 220 sq m2/g with little affect on the modulus, elastic recovery, porosity, or density

High T(sub g) Polymides for Resin Transfer Molding

A series of new polyimide resins with low melt viscosities and high glass transition temperatures (T(sub g)'s) of 340-350 C were developed for resin transfer molding (RTM) applications. The viscosities of these polyimide resins, based on 2,3,3'4'-Biphenyltetracarboxylic Dianhydride (a-BPDA), are in the range of 10-30 poise. The composites were fabricated successfully at 260-280 C with a pot life of 30-60 minutes by the RTM process. The viscosity profiles of the polyimide resins and the mechanical properties of the polyimide carbon fiber composites will be discussed

Graphics, Visualization, and Usability Center

Graphics, Visualization, and Usability (GVU) is an interdisciplinary area which draws its intellectual foundations from Computer Science, Psychology, Industrial and Systems Engineering, and Computer Engineering, and which has application to any use of computers to graphically convey information to users. Typical applications are computer aided design, scientific and business data visualization, multimedia, computer-supported cooperative work, computer-based teaching, image understanding, medical imaging, and user interface design. The GVU Center has three missions: education, service, and research. In our educational role, we teach the principles and methods of computer graphics, visualization, and usability to members of the academic community ranging from undergraduate students to graduate students and faculty. Center members teach dozens of courses and seminars among the wide offering of relevant courses listed in Section F. A set of continuing education short courses (Section G) are provided to assist practitioners to stay abreast of current developments. Our service mission is carried out through the Scientific Visualization Lab, a joint undertaking with Information Technology (the campus-wide computer service), to provide state of the art computer graphics hardware and software capabilities to the entire Georgia Tech Community. Over 150 faculty, graduate students and staff use the visualization lab's facilities. Our research, described in Section B, spans the areas of realistic imagery, computer-supported collaborative work, algorithm animation, medical imaging, image understanding, scientific data visualization, animation, user interface software, usability, adaptive user interfaces, multimedia, stereo graphics, virtual environments, image quality, and expert systems in graphics and user interfaces. The twenty faculty and staff who are actively developing the lab's programs are drawn from Psychology, Mechanical Engineering, Office of Interdisciplinary Programs, Physics, Mathematics, Information Technology, and the College of Computing. An active seminar series and brown-bag lunches brings us together every week to discuss current research topics. By integrating these three missions together in a single unit, the Center is developing a highly interactive and collaborative environment where researchers unfamiliar with computer graphics can come for help in integrating scientific visualization into their research work, graphics experts and graduate students can share thier knowledge with one another and find new and interesting problems on which to work, and students can learn in a melting pot of closely-related ideas and collaborations between researchers from multiple disciplines. This intellectually-stimulating environment, complemented by over 40 workstations and other pieces of equipment and over 3000 square feet of newly-renovated lab space, provides a paradigm for the use of interactive computer graphics systems which will be necessary for engineering and scientific research in the 21st century