Polymeric Foams

Postprint (published version

Structural Framework for Flight: NASA's Role in Development of Advanced Composite Materials for Aircraft and Space Structures

This serves as a source of collated information on Composite Research over the past four decades at NASA Langley Research Center, and is a key reference for readers wishing to grasp the underlying principles and challenges associated with developing and applying advanced composite materials to new aerospace vehicle concepts. Second, it identifies the major obstacles encountered in developing and applying composites on advanced flight vehicles, as well as lessons learned in overcoming these obstacles. Third, it points out current barriers and challenges to further application of composites on future vehicles. This is extremely valuable for steering research in the future, when new breakthroughs in materials or processing science may eliminate/minimize some of the barriers that have traditionally blocked the expanded application of composite to new structural or revolutionary vehicle concepts. Finally, a review of past work and identification of future challenges will hopefully inspire new research opportunities and development of revolutionary materials and structural concepts to revolutionize future flight vehicles

Polymer Processing and Surfaces

This book focuses on fundamental and applied research on polymer processing and its effect on the final surface as the optimization of polymer surface properties results in the unique applicability of these over other materials. The development and testing of the next generation of polymeric and composite materials is of particular interest. Special attention is given to polymer surface modification, external stimuli-responsive surfaces, coatings, adhesion, polymer and composites fatigue analysis, evaluation of the surface quality and microhardness, processing parameter optimization, characterization techniques, among others

Thermoplastic Elastomers

Thermoplastic elastomers (TPEs), commonly known as thermoplastic rubbers, are a category of copolymers having thermoplastic and elastomeric characteristics. A TPE is a rubbery material with properties very close to those of conventional vulcanized rubber at normal conditions. It can be processed in a molten state even at elevated temperatures. TPEs show advantages typical of both rubbery materials and plastic materials. TPEs are a class of polymers bridging between the service properties of elastomers and the processing properties of thermoplastics. Nowadays, the best use of thermoplastics is in the field of biomedical applications, starting from artificial skin to many of the artificial human body parts. Apart from these, thermoplastic elastomers are being used for drug encapsulation purposes, and since they are biocompatible in many cases, their scope of applications has been broadened in the biotechnological field as well. The present book highlights many biological and biomedical applications of TPEs from which the broader area readers will benefit

MANUFACTURE AND CHARACTERIZATION OF POLYVINYL CHLORIDE / POLYETHYLENE PVC / PE COMPOSITES FOR STRUCTURAL APPLICATIONS

The research initially studied a safe recycling process that decreases the accumulation of thermoplastic wastes and prevents pollution of the environment. Obtained all composites in these works were analyzed for mechanical, thermal, and morphological dynamical- mechanical and rheological characteristics. This research aims to develop a new polyvinylchloride (PVC) microcomposite that incorporates low density polyethylene (LDPE), calcium carbonate (CaCO3), and calcium/zinc stearate (CaSt2/ZnSt2). The addition of 5 phr of CaSt2: ZnSt2 = 9:1 into PVC appears to yield an optimal mechanical result and shows high thermal stability. Moreover, when a heat stabilizer rich in calcium is mixed with CaCO3 and LDPE, an excellent synergistic effect is demonstrated. The properties of polyvinyl chloride (PVC) and low density polyethylene (LDPE) blends, at three different ratios (20, 50, and 80 wt.%) of renewable LDPE were studied. Besides, Biobased composite with PVC-LDPE blend and date palm fiber as reinforcement at different loading levels (0-30 wt.%) were also investigated. The matrix in which PVC-LDPE (20 wt.%-80 wt.%) had the optimum mechanical and thermal properties. The modulus of the composites is enhanced with increasing DPLF content. Scanning electron microscopic micrographs revealed that morphological properties of fracture surfaces are following the tensile properties of these blends and composites. Thermal analysis showed that the thermal degradation of PVC-LDPE (20 wt.%/80 wt.%) blend and PVC-LDPE-DPLF (10 and 30 wt.%) composites took place in two steps: in the first step, the blend was more stable than the composites. In the second step, the composites showed slightly better stability than the PVC-LDPE (20 wt.%-80 wt.%) blend. Leaflets and rachis fibers (DPFs) were used as a sustainable reinforcement material to strengthen PVC-HDPE (20:80) biocomposites to further study the feasibility of compounding date palm fiber. As this renewable material used in this project work are crop wastes, the fibers had to be pre-treated to eliminate lignin and impurities for enhancing the interfacial adhesion between matrix and fiber, composites with untreated and treated DPFs containing 30 wt% were produced. Infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) have confirmed the enhancement of surface modification of DPFs from the delignification process to the extraction of cellulose microcrystals (CMCs). Furthermore, structural, morphological, thermal, mechanical, dynamic-mechanical, rheological, and water absorption all improved the biocomposites characteristic performances as a function of the modified DPFs. Hence, the PVC HDPE-HNO3F composite reveals a selective advantage to be a good potential candidate for several structural application

Pneumatic Tire

For many years, tire engineers relied on the monograph, \u27Mechanics of Pneumatic Tires\u27, for detailed information about the principles of tire design and use. Published originally by the National Bureau of Standards, U.S. Department of Commerce, in 1971, and a later (1981) edition by the National Highway Traffic Safety Administration (NHTSA), U.S. Department of Transportation, it has long been out of print. No textbook or monograph of comparable range and depth has appeared since. While many chapters of the two editions contain authoritative reviews that are still relevant today, they were prepared in an era when bias ply and belted-bias tires were in widespread use in the United States and thus did not deal in a comprehensive way with more recent tire technology, notably the radial constructions now adopted nearly universally. In 2002, it was preposed that NHTSA should sponsor and publish electronically a new book on passenger tires, under editorship of the University of Akron, to meet the needs of a new generation of tire scientists, engineers, designers, and users. This text is the outcome. The chapter authors are recognized authorities in tire science and technology. They have prepared scholarly and up-to-date reviews of the various aspects of passenger car tire design, construction and use, and included test questions in many instances, so that the book can be used for self-study or as a teaching text by engineers and others entering the tire industry

Structural Framework for Flight I: NASAs Role in Development of Advanced Composite Materials for Aircraft and Space Structures

This monograph is organized to look at: the successful application of composites on aircraft and space launch vehicles, the role of NASA in enabling these applications for each different class of flight vehicles, and a discussion of the major advancements made in discipline areas of research. In each section, key personnel and selected references are included. These references are intended to provide additional information for technical specialists and others who desire a more in-depth discussion of the contributions. Also in each section, lessons learned and future challenges are highlighted to help guide technical personnel either in the conduct or management of current and future research projects related to advanced composite materials

Construction Materials in the Productions of Inorganic Substances

The textbook «Construction Materials in the Productions of Inorganic Substances» belongs to the cycle of disciplines professional and practical training. Textbook «Construction Materials in the Productions of Inorganic Substances» is the basis for profile disciplines in the curriculum of specialist training 161 «Chemical technologies and engineering» specialization «Chemical technologies of inorganic substances and water purification». The subject of the textbook «Construction Materials in the Productions of Inorganic Substances» has an important role in shaping the outlook of a modern specialist in the technology of inorganic substances. The educational material of the textbook «Construction Materials in the Productions of Inorganic Substances» is based on the knowledge of courses in physics, general and inorganic chemistry, and also forms the basis for further study of such more profound disciplines as Chemical technology of inorganic substances. Textbook «Construction Materials in the Productions of Inorganic Substances» has the purpose of studying the theoretical foundations of materials science on the basis of general connections between the internal structure of the material and its properties

NASA Tech Briefs, Fall 1982

Topics include: NASA TU Services: Technology Utilization services that can assist you in learning about and applying NASA technology. New Product Ideas: A summary of selected innovations of value to manufacturers for the develop ment of new products; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences