N. Thornton Lipscomb

Professor, Organic Chemistry: Physical Polymer Chemistry


The Production of Eyeglass Lenses by UV Photosensitized Polymerization

At the present time plastic eyeglass lenses are produced by grinding plastic blanks. This research is focused on molding plastic lenses that would require grinding. The technique involves adding a photosensitizer to the monomer mixture. The mixture is then placed in a glass mold and exposed to UV light. The photosensitizer is activated by the UV light and initiates polymerization. When the lens is removed from the mold it has all the qualities of a finished lens. (It is hard, rigid, clear, and optically perfect.) The present research deals with several facets: Possible directions of research are (1) monomer synthesis: preparation of new monomers that would produce polymers that have certain characteristics such as high refractive indices, stability with acids or bores, resistance to degradation from heat or light, and high clarity. Monomers that shrink little or none in polymerization are also of interest. Other directions include (2) copolymerization. Parameters to explore include monomer type and concentration, UV intensity, and temperature. The understanding of how the individual monomers polymerize together and how each affects the properties of the polymer is the goal.