Author : Mohammed Jaradat
Publisher :
ISBN 13 :
Total Pages : 173 pages
Book Rating : 4.:/5 (94 download)
Book Synopsis Environmental Degradation of Nano Enhanced Polymers in Low Earth Orbit by : Mohammed Jaradat
Download or read book Environmental Degradation of Nano Enhanced Polymers in Low Earth Orbit written by Mohammed Jaradat and published by . This book was released on 2014 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers are widely used in space shuttles and systems due to the unique properties they possess. However, the extremely harsh conditions in the low earth orbit (LEO), which ranges from 200-1800 km above the earth, have a degrading effect on those polymers. The predominant component of the LEO atmosphere is Atomic Oxygen (AO), which is a single O atom formed through the dissociation of molecular oxygen by ultra violet radiation from the sun. AO particles collide with a kinetic energy of approximately 5 eV, this energy is enough to facilitate the degradation of most polymers. An organic/inorganic hybrid material approach is used in this study through the incorporation of polyhedral oligomeric silsesquixanes (POSS) into traditional polymer systems. Several materials with different POSS percentages and exposure times to oxygen plasma (glassification process) are considered for this research. Following a pre-testing process only selected specimens are sent to the atomic oxygen testing facility at Marshall Space and Flight Center to be tested and evaluated. The specimens were assessed using the dynamic mechanical analysis and atomic force microscopy techniques to characterize the surface and obtain different mechanical and physical properties. A computational approach in the form of Molecular Dynamics (MD) simulations are performed on a polyimide and polyimide/POSS systems and elastic properties are determined. The selected materials with higher POSS percentages generally performed better in terms of mass loss of the tested systems due to the rapid and more complete formation of an oxidized protective layer that significantly limits further degradation once it formed. The glassification process doesn't seem to improve the resistance against AO attacks greatly at such small exposure times, never the less a slight improvement is noticed.