Synthesis and cationic photopolymerization of novel monomers based on dicyclopentadiene

A series of novel epoxide monomers and oligomers based on dicyclopentadiene (DCPD) were prepared using straightforward synthetic methodology. The diff erentiated reactivity of the two double bands in DC PD makes it possible to conduct the addition of alcohols and silanes preferentially at the norborn enyl double bond. Epoxidation of these adducts afforded mono- and difunctio nal monomers bearing epoxycyclopentyl groups. These epoxide monomers displa y excellent reactivity in the photoinitiated cationic ring-opening polymeri zations using diaryliodonium salt and other onium salt photoinitiators. The high reactivity of these novel DCPD monomers can be attributed to the high ring strain present in the epoxycyclopentyl ring system. Also prepared dur ing the course of this work were two inorganic/organic hybrid systems in wh ich epoxy. DC PD moieties are placed as pendant groups onto a siloxane back bone. Photopolymerization of these oligomers also takes place very rapidly under UV irradiation conditions to yield glassy resin matrixes with very go od thermal oxidative resistance.