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Optics. Good optical properties and low thermal resistance make poly(methyl methacrylate) polymers well suited for use as plastic optical fibers. The manufacturing methods and optical properties of the fibers have been reviewed (124) (see Fiber optics). Methods for the preparation of Fresnel lenses and a Fresnel lens film have been reported (125,126). Compositions and methods for the industrial production of cast plastic eyeglass lenses are available (127). 

Scratch resistance of polymer from DADC is improved by novel mixtures of peroxide initiators such as 5% isopropyl percarbonate with 3.5% benzoyl peroxide (16). In order to force completion of polymerization and attain the best scratch resistance in lenses, uv radiation is appHed (17). Eyeglass lenses can be made by prepolymerization in molds followed by removal for final thermal cross-linking (18). 

DADC may be polymerised industrially with small amounts of other miscible Hquid monomers. Some acryflc ester monomers and maleic anhydride may accelerate polymerisation. Copolymerisation with methacrylates, diaHyl phthalates, triaHyl isocyanurate, maleates, maleimides, and unsaturated polyesters are among the examples in the early Hterature. Copolymers of DADC with poly-functional unsaturated esters give castings of high clarity for eyeglass lenses and other optical appHcations (20). 

Chains that include aromatic rings (phenols, pyridines, etc.) are said to be polycyclic and are stiffer, harder and more stable than aliphatic chains. Polycarbonate is an example, being hard enough for use in eyeglass lenses. An extreme example is Kevlar fiber. 

Imagine the possibilities, some of which are just now becoming reality Tools, knife blades, and scalpels coated with diamond remain forever sharp. Eyeglass lenses and wristwatches coated with diamond remain scratch-free. High-fidelity loudspeakers coated with diamond give a nearly perfect, undistorted sound at high frequencies. Hip joints and other biological implants coated with diamond are not rejected by the body s immune system. 

Lexan is a plastic used to make compact discs, eyeglass lenses, and bullet-proof glass. One of the compounds used to make Lexan is phosgene (COCI2), a poisonous gas. Phosgene is produced by the reaction... 

Coatings is a diversified application area involving a substrate and some type of surface covering. The type of substrate material to be coated can be plastics such as polycarbonate or polypropylene, metals, silicone rubber, ceramic- or refractory-like materials, fabrics like nylon and rayon, photographic films, paper materials, walls (painted or not), eyeglass lenses,... 

Other types of polycarbonates have also been made using a very different approach from that involving bisphenol A and related compounds. For example, the reaction between phosgene and allyl alcohol (CH2=CHCH2OH) produces a monomer with carbon-carbon double bonds at both ends of the molecule that can be used for polymerization. Interestingly enough, the polycarbonate produced by this process has very different physical properties from the traditional bisphenol A polymer. The allyl polymer is a clear, transparent, flexible plastic whose primary use is in the production of eyeglass lenses. 

Shatterproof eyeglass lenses, CDs, DVDs, bulletproof windows, greenhouses... 

Phosgene is a highly toxic gas that has been used as a chemical weapon at times in the past. It is now used in the manufacture of polycarbonates, which are used to make compact discs and plastic eyeglass lenses. Phosgene is produced by the reaction, CO + CI2 — COCI2. Given an excess of carbon monoxide, what mass of chlorine gas must be reacted to form... 

Major Applications Organic light emitting devices, electroluminescent devices, laser dyes, photography, plastic scintillation applications, 3 herbicides, eyeglass lenses, cosmetics Safety/Toxicity Endocrine disrupters " ... 

Melzig, M. Plastic eyeglass lenses with fluorescent markings. Ger. Offen. DE 3544627, 1987 Chem. Abstr. 1987,107, 155544. 

The addition of silver halide crystals to eyeglass lenses allows them to rapidly change from clear to dark. Ultraviolet light hits the crystals, causing a chemical change that blocks light and darkens the lenses. 

Optics. Polymethacrylates are naturally good choices for the fiberoptics market because of their optical clarity and low thermal resistance (137). Fresnel and eyeglass lenses have been made using polymethacrylates (138-140). 

Casting is a process that most closely reflects baking a cake. Just like cake batter is poured into a pan, molten polymer is poured into a mold. This process yields items such as eyeglass lenses. 

Tinted eyeglass lenses or visor-type shade. 

Summary of Important Tests of ORMOSIL Coated Eyeglass Lenses. 

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