PREPARATION OF 1-PROPENYL ETHER FUNCTIONAL SILOXANES BY CHEMOSELECTIVE HYDROSILATION AND THEIR CATIONIC PHOTOPOLYMERIZATION

Using model compounds, it was shown that the hydrosilation of (1-propenoxy)norborn-5-enes takes place chemoselectively only at the norbornene double bond. Accordingly, a variety of mono-, di-, and multifunctional 1-propenyl ether substituted siloxanes were readily prepared in high yields by the hydrosilation of (1-propenoxy)norborn-5-enes with various linear and cyclic hydrogen functional siloxanes. These new monomers and oligomers undergo rapid photoinduced cationic polymerization in the presence of onium salt photoinitiators. To study these very fast photopolymerizations, extensive use of Fourier transform real-time infrared spectroscopy was made. Employing this technique, the effects of monomer and photoinitiator structure on the rates of polymerization were studied.