The invention comprises a method of producing an interpenetrating polymer
network (IPN) comprising the steps of I) providing a silicone polymer
composition; (ii) providing one or more monomers for a polymer; (iii)
providing a solvent for the one or more monomers; iv) exposing said
silicone polymer composition to said one or more monomers and said
solvent to precipitate monomer within said silicone polymer composition
and v) polymerizing said monomer to form an IPN, wherein said solvent has
a surface tension at the exposing step of about 15 mNZm or less. It is
preferred that the solvent, which is preferably CO.sub.2, in the exposing
step is in or near its supercritical state. The method is fast and
simple, and the dispersion of the monomers may be controlled to thereby
control the amount and distribution of the interpenetrating network in
the silicone material. Further more the method results in new materials,
where silicone polymers are used as the basic materials.