Property changes induced by the space environment in polymeric materials on LDEF

Author(s):  
ANN WHITAKER ◽  
MIRIA FINCKENOR ◽  
RACHEL KAMENETZKY
1989 ◽  
Vol 43 (8) ◽  
pp. 1387-1393 ◽  
Author(s):  
William F. McDonald ◽  
Hans Goeitler ◽  
Marek W. Urban

A new rheo-photoacoustic Fourier transform infrared cell has been developed to perform stress-strain studies on polymeric materials. The rheo-photoacoustic measurements lead to the enhancement of the photoacoustic signal and allow one to monitor the effect of elongational forces on the molecular structure of polymers. Propagating acoustic waves are detected as a result of the deformational changes and thermal property changes upon the applied stress. Applications of this technique to fibers, films, and adhesion of thin films are presented.


2013 ◽  
Vol 787 ◽  
pp. 35-39 ◽  
Author(s):  
Shi Chao Liu ◽  
Jie Cai ◽  
Le Ji ◽  
Zai Qiang Zhang ◽  
Xiu Li Hou ◽  
...  

The microstructures and properties of 2024 aeronautical aluminum alloy subjected to thermal cycling were investigated in simulated Low Earth Orbit space environment. The experimental results demonstrate that the microhardness of aluminum alloys changed with the increasing of thermal cycles. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) show that the property changes of the 2024 aluminum alloys during the thermal cycling period are closely related to the microstructural evolution. The relationship between the microstructural evolution and the thermal fatigue was also discussed.


1994 ◽  
Vol 9 (4) ◽  
pp. 1043-1050 ◽  
Author(s):  
E. H. Lee ◽  
G. R. Rao ◽  
M. B. Lewis ◽  
L. K. Mansur

It has been shown that ion implantation produces remarkable improvements in surface-sensitive mechanical properties, as well as other physical and chemical properties in polymers. To understand mechanisms underlying such property changes, various polymeric materials were subjected to bombardment by energetic ions in the range of 200 keV to 2 MeV. The magnitude of property changes is strongly dependent upon ion species, energy, and dose. Analysis indicated that hardness and electrical conductivity increased by employing ion species with larger electronic cross sections and with increasing ion energy and dose. The results showed that electronic stopping or linear energy transfer (LET, energy deposited per unit track length per ion) for ionization was the most important factor for the enhancement of hardness, while nuclear stopping or linear energy transfer for displacement generally appeared to reduce hardness.


2004 ◽  
Vol 851 ◽  
Author(s):  
David L. Edwards ◽  
Mircea Chipara

ABSTRACTThe feasibility and the performance of solar sail depend critically on the availability of light materials and extremely thin polymeric films. The main requirements imposed on solar sail materials are analyzed in depth. The potential effects of the space environment are discussed in detail, with emphasis on the radiation-temperature-polymeric film thickness relationships. It is shown that the radiation component of the space environment triggers two competing degradation processes (erosion and depolymerization) and that both processes act towards the decrease in the glass transition temperature.


2013 ◽  
Vol 86 (12) ◽  
pp. 367-372
Author(s):  
Kazuyuki MORI ◽  
Eiji MIYAZAKI

2021 ◽  
Vol 11 (3) ◽  
pp. 949
Author(s):  
Roberto Pastore ◽  
Marta Albano ◽  
Andrea Delfini ◽  
Fabio Santoni ◽  
Mario Marchetti

Space-mission development introduced the problem of human isolation in extreme environments. The integration of architectural concepts such as windows, with their technical implications into human space missions, is necessary especially for long-duration space flights. Such solutions must be subjected to close certification testing in order to establish their compliance with severe space environment conditions. Moreover, projects of long-term missions involve a renewed concern about fire safety in manned space vehicles. The supposed occupancy time of the order of decades, in fact, makes unplanned fire ignition events virtually unavoidable. An experimental test-plan performed to qualify a commercial thermoplastic material for applications as transparent element in spacecraft is reported in the present work. A flame exposure test, as well as ultraviolet radiation and atomic oxygen erosion rate measurements, was carried out on a commercial poly-sulfone material, following ASTM standard procedures. The aim of the research was to develop and put forward flame retardant structures able to withstand the harsh space environment, preventing or mitigating the degradation of their physical and chemical integrity, with particular regard to the visible-light transparency. The results obtained show that the tested poly-sulfone may be considered as a promising material for the claimed application, even if further surface optimization treatments should be conceived in order to gain a full adaptability to the operative constraints.


2004 ◽  
Vol 851 ◽  
Author(s):  
David Hui ◽  
Magdalena D. Chipara

ABSTRACTRadiation-induced modifications in polymeric materials are briefly reviewed. The attention is paid to the effect of ionizing radiation on the mechanical properties of polymers. The competition between several parallel degradation processes in the harsh conditions of the space environment is analyzed. The need for a complex analysis of the effect of polymeric materials in simulated space environments is demonstrated.


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