**3.2.1.5 Radical polymerization of dissymmetric fumarates**

Polymerization of fumarate monomers provide polymers with a substituent in every methylene unit. These polymers are applied as high performance materials, as biodegradable polymers, low dielectric materials, oxygen permeability membranes, liquid crystal, contact lens (CL) materials, etc. Among them, CL is known well as the lens equipped on a cornea foe vision correction, and the CL materials are required both for the oxygen permeable property for breathing of corneal cell and the hydrophilic property for not repelling a tear and to protect a lipid deposition. Polymerizations of amphiphilic fumarate (containing hydrophilic and hydrophobic substituents) monomers give polymers with high oxygen permeability, hydrophilicity and transparency required for CL materials. Novel dissymmetric fumarate monomers having both alkoxyethyl group [2-(2-methoxyethoxy) ethyl, 2-(2-(2-methoxy-ethoxy)ethoxy)ethyl] and a bulky 3-[tris(trimethylsiloxy)silyl]propyl group were radically polymerized with styrene and N-vinylpyrrolidone (NVP). Various membranes, prepared by copolymerization of fumarate monomers with NVP or NVP and HEMA, showed much better transparency, as compared to the membranes containing 3- [tris-(trimethylsilyloxy)silyl]propyl methacrylate (Ohnishi et al. 2009).
