Investigation of Epoxy Matrix Resistance Against the Low Earth Orbit Environment by Adding MWCNT and Nano-Silica

摘要

Although composites have high specific strength and low coefficient of thermal expansion, the various hazards of the Low Earth Orbit(LEO) environment causes damage mostly on the surface of polymer matrix composites, creating microcracks, bringing about the degradation of mechanical properties, and resulting in dimensional changes. Generally, epoxy matrix is commonly used for composites but epoxy material does not display sufficient resistance against the attack of atomic oxygen and extreme thermal cycling. Thus, nano-fillers have been used to reinforce the epoxy matrix. Therefore, in this study, the resistance of multi-walled carbon nanotube(MWCNT) and nano-silica reinforced epoxy matrix was evaluated under 20 hours of simulated LEO environment involving 10~(-4)torr high vacuum, 200nm UV radiation, 14 thermal cycles ranging from-70~100°C, and AO fluence of 9.15x 10~(14)atoms/cm~2s. The mass loss of the specimens after aging under the simulated LEO environment was measured and the resistance was differentiated by analyzing the degree of variation of measured tensile properties according to ASTM D638. Moreover, in order to minimize agglomeration, a 3-roll mill equipment was used to evenly disperse the nano-filler within the matrix. The addition of nano-fillers reduced the surface damage from AO exposure to some extent, the material mass loss, and the degree of tensile properties reduction.