Epoxide, catalyst, molding

Generally these compositions contain an epoxy-novolac, a hardener, a catalyst, silica fillers, and an internal lubricant/mold release compound. Brom-inated epoxies and antimony trioxide are included to provide the required flame retardant characteristics. Other, unspecified additives are used to promote adhesion or to reduce corrosion rates. Because of their superior thermal capabilities and electrical properties, epoxidized novolacs are preferred over epoxy homopolymers. Near stoichiometric amounts of hardeners such as novolacs (Equation 1), anhydrides, and primary amines can be used to cure the resins in the presence of a catalyst. The linkages which are formed include ethers, esters, or secondary amines, respectively. 

Two molding methods were adopted to prepare the titanium silicalite catalyst used in a fixed bed reactor. One is the traditional extruding method in which strip TS-1 catalyst is obtained. The other is a new kind of molding method in which lamina TS-1 catalyst is made by spraying the powdery TS-1 on a small inert ball. The lamina TS-1 catalyst exhibits better performance in propylene epoxidation than the strip TS-1 catalyst. 

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