Influence of various catalysts on the radiation resistance and the mechanical properties of cyanate ester/epoxy insulation systems

Fiber reinforced composites impregnated with mixtures of various cyanate ester and epoxy resins demonstrated their excellent performance at the ITER design fluence and beyond. The insulation systems consist of a wrapped R-glass/Kapton reinforcement, vacuum impregnated with a cyanate ester/epoxy blend. For the fabrication of the insulation a long pot-life of the resin is of great importance, which is mainly determined by the amount and the composition of the catalyst needed for curing the resin. However, the catalyst, which amounts to 1-2% of the resin, may also affect the mechanical properties as well as the radiation hardness of the material. In order to investigate these effects, two different composites were fabricated using a Mn- and a Co-catalyst, respectively. The mechanical properties are characterized prior to and after irradiation to a fast neutron fluence of 1 x 1022 m-2 (E > 0.1 MeV) in tension and interlaminar shear at 77 K.