New synthesis of photocurable silanes and polysiloxanes bearing heterocyclic or olefinic functions

In this work, we described the synthesis of silanes and polysiloxanes beari ng cationic photopolymerizable groups. Two new methods were used. The first one is the reaction between 3-mercapto-propyl-1-triethoxysilane (1) and ch loromethylated olefins by a phase transfer catalysis. The second one is the radical addition of (1) or poly(dimethylsiloxane-co-methylmercaptopropylsi loxane (9) to allyl or vinyl substituted heterocyclic monomers. These metho ds led to the expected adducts with an excellent yield. The polysiloxanes b earing heterocyclic functional groups linked through thioether bonds were p hotocurable by cationic route. Under UV light intensity of 17.5 mW/cm(2), t hese polymers harden after 15 or 20 s. (C) 1999 Elsevier Science B.V. All r ights reserved.