SYNTHESIS OF OLIGOMERS OF CROSS-LINKABLE POLYDIMETHYLSILOXANE .1. INTRODUCTION OF ACRYL GROUPS TO POLYDIMETHYLSILOXANES CONTAINING 3-HYDROXYPROPYL GROUPS

We describe the synthesis of polydimethylsiloxane with 3-hydroxypropyl in the chain or at the ends by copolycondensation of 3-acetoxypropyl methyl dichlorosilane with various alpha, omega-disilanols. The length of the chain was controlled by addition of vinyl or 3-acetoxy propyl monochloro dimethyl silane. Methacryoyl chloride was then grafted to give a polyunsaturated product. These oligomers were crosslinked by u.v. with reactive diluents and photoinitiators to give products with very good "release properties" especially with the longer siloxane chains.