The effect of electron radiation on POSS/cyanate ester nanocomposites

Electron irradiation in outer space is a nonnegligible environmental factor that causes severe damage to the polymeric materials used in spacecraft. To improve the irradiation resistance of cyanate ester (CE), which is ubiquitous in space structures, polyhedral oligomeric silsesquioxane (POSS) was added to the cyanate ester resin to fabricate the nanocomposite. The effects of electron irradiation on CE resin and POSS/CE nanocomposites were examined in terms of mass loss, flexural strength, surface morphology, and surface chemical structure. Experimental results show that electron irradiation induces two reactions among the cyanate ester resin. Irradiation fluences less than 1.0 x 1016 e/cm2, the cross-linking reaction among the cyanate groups increases flexural strength. However, a further increase in fluence and degradation effects cause a decrease in flexural strength. Under high radiation fluence, the CE resin matrix's skeletal structure is somewhat destroyed, releasing small molecules from the material's surface. Additionally, when the charges cumulate to a certain extent, the electric discharge results in the ablating of the resin surface. The damage effect of POSS/CE composites under the same conditions of electron irradiation is similar to that of CE. However, the magnitude of damage of the POSS/ CE composites is lower, showing better resistance to electron irradiation.