Bulk polymerization and copolymerization have been affeeted to > 95 conversion by X-irra- diation. Polymers of metliyi methacrylate (MMA) and its copolymers were prepared with 2- hydroxyethyl methacrylate (HEMA), hexamethyl disiloxane (HMDS), and polypropylene glycol (PPG) in the presence and absence of a crosslinking agent. The optieal homogeneity (classified as opacity, transluceny or transparency), density, equilibrium water content, percent hydration, and thermal properties were examined, The influences of dose, presence’ of crosslinker atnount and type of comonomer on these properties were investigated.