Curable inter-polymer optical fiber cladding compositions

A method for producing an optically clear, cladding inter polymer with a low refractive index on a silica or plastic optic fiber comprising the steps of

• (a) providing one or more monomers selected from monomers of the formula:
• CH.sub.2 .dbd.C(R) COOCHXY
• wherein
• R is hydrogen or methyl,
• X is hydrogen or perfluoromethyl,
• Y is hydrogen or perfluoromethyl, providing that if X is hydrogen then Y is (CH.sub.2)n (CF.sub.2)m Z wherein
• Z is hydrogen or fluorine,
• n is 0 to 4 and
• m is 1 to 10;
• (b) polymerizing the one or more monomers in the presence of a polymerization initiator and a polymer chain transfer agent to form a low molecular weight soluble pre-polymer;
• (c) dissolving the pre-polymer in monomers of the same formula provided in step (a) in the presence of an ultra violet or thermal polymerization initiator to form a reactive pre-polymer solution;
• (d) admixing a cross-linking di- or poly-functional acrylate or methacrylate ester with the reactive pre-polymer solution;
• (e) applying the solution of (d) to an optical fiber and
• (f) initiating the polymerization of the solution of (d) to form a cured cladding polymer on the optical fiber.