Study Of Poss Modified Materials With Both UV Resistance And High Temperature Stability

The LEO space is a complex dynamic environment. The ultraviolet radiation has a strong corrosive effect on near-space vehicle surface material, and greatly reduces the spacecraft’s service life. Therefore, the development of resistance to ultraviolet radiation for near-space protection materials has important significance. Recent years, as a novel organic/inorganic hybrid materials, polyhedral oligomeric silsesquioxane (POSS) can be modified to many materials to abtain required properties, such as the thermal stability, UV resistance and mechanical properties.The novel curing agent octaaminophenyl polyhedral oligomeric silsesquioxane(OAPS) was synthesized. Then we prepared a series of UV protection coating materials by in-situ polymerization method, with OAPS as the inorganic precursor and the polyether, polydimethylsiloxane and star-shaped poly(urea-imide) (PUI) as matrix resin. The effect of POSS on the heat resistance, mechanical properties and UV resistance of the materials was studied by changing the content of OAPS. The material were exposed to ultraviolet radiation for about 48 hours, in order to investigate the effects of OAPS and PUI structure on UV resistance of the coating material. It can be seen that POSS-modified star-shaped poly (urea-imide) exhibits excellent heat decomposition resistance, and the highest initial decomposition temperature is up to 340℃. POSS-modified polydimethylsiloxane poly(urea-imide) exhibits the best UV resistance. It also indicates that POSS can effectively improve the UV resistance of composite materials, because When exposed to ultraviolet radiation, the material surface form a SiO2 ceramic layer to avoid further corrosion.