Study On Nano-TiO₂ Modified Cyanate Ester Composite And Its Resistance Of Vacuum Electrons Radiation

High-performance resin matrix composites have important applications in aerospace structures,airerafts and civil industry have gain more and more attentions at present. As one of new advanced matrix,cyanate esters are considered as the key resin matrix system in the high-performance resin matrix composites. However,the brittleness as most hermosetting resins has limited their applications. In this paper,aiming at the brittleness of solidified cyanate ester, nano-TiO₂ was selected to tough cyanate ester due to its unique surface effect. The effect of nano-TiO₂ on mechanical properties of cyanate ester was inverstigated. The changes in mechanical properties, mass loss and thermal expansion coefficients were meassured before and after the 160Kev electron irradiation . The micro structure of the composite was analyzed and characterized using FT-IR,EPR and SEM.Experimental results show that Cyanate ester resin and graphite fiber/cyanate ester composite can be enhanced and toughened by nano-TiO₂; When the content of nano-TiO₂ is 3%, a 43% increase in the tensile strength and a 33% increase in the bend strength of nano- TiO₂/cyanate ester composites was obtained compared to that of no-nano composites, respectively, the tensile strength and interlayer shear strength of graphite fiber/cyanate ester composites are improved about 10% and 18%.Under the irradiation energy of 160 kev, there are increases in tensile and bend strength of casting, bend and interlayer shear strength of the composites firstly and then descend with the irradiation flux increases. With increasing fluence. the mass loss of cyanate ester casting and graphite fiber /cyanate ester composites accordingly increases and then becomes steady, and the mass loss of cyanate ester casting is bigger than others ,The mass loss is attributed to the volatilization of the gas,the solvent and the small molecule assistant adsorbed on material , and to small molecules escape produced by the breakage of chemical bond. The properties of the composite have a close relationship with the cross-linking density of the resin under internet with electron irradiation.