UV curing of epoxy functional hybrid silicones

Several epoxy difunctional hybrid alkylene-silicone telomers with different silicone characters and organic spacers (linkers) were prepared via the platinum-catalyzed polyhydrosilylation of α,Ï-dihydrosiloxanes and α,Ï-dienes. Thereafter, the resulting Si-H-terminated prepolymers were terminally functionalized with 4-vinyl-1,2-epoxycyclohexane or allyl glycidyl ether. In the presence of a lipophilic cationic photoinitiator, the terminally epoxy-functionalized hybrid alkylene-silicone telomers were photopolymerized to give crosslinked, soft, elastomeric, and transparent films. The progress of the photoinitiated cationic ring-opening epoxide polymerizations was monitored using optical pyrometry. Potential applications for these novel photocurable epoxy-functional telomers are as modifiers for UV curable coatings, printing inks, adhesives, and release coatings.