Bulletproof windows

Did you know that redox reactions are an important part of CD manufacturing The CDs you huy at a music store are made of Lexan , the same plastic used for riot shields and bulletproof windows. The CDs are coated with a thin aluminum film. They are copies of a single master disc, which is made of glass coated with silver, as seen in Figure 10.9. Silver is deposited on a glass disc hy the reduction of silver ions with methanal, HCHO, also known as formaldehyde. In the same reaction, formaldehyde is oxidized to methanoic acid, HCOOH, also known as formic acid. The redox reaction occurs under acidic conditions. 

The dots dart through the closed, bulletproof window and shoot toward Pennsylvania Avenue. Sally is the first out of the White House to follow them. You and Narcinko are close behind. 

Polycarbonates and Polyurethanes The chemistry of carbonic acid derivatives is particularly important because two large classes of polymers are bonded by linkages containing these functional groups the polycarbonates and the polyurethanes. Polycarbonates are polymers bonded by the carbonate ester linkage, and polyurethanes are polymers bonded by the carbamate ester linkage. Lexan polycarbonate is a strong, clear polymer used in bulletproof windows and crash helmets. The diol used to make Lexan is a phenol called bisphenol A, a common intermediate in polyester and polyurethane synthesis. 

Polyesters with two ester groups bonded to the same carbon are known as polycarbonates. Lexan is produced by the reaction of phosgene with bisphenol A. Lexan is a strong, transparent polymer used for bulletproof windows and traffic-light lenses. In recent years, polycarbonates have become important polymers in the automobile industry as well as in the manufacture of compact discs. 

Safety devices, including helmets, goggles, and bulletproof windows ... 

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

Polymethyl methacrylate Skylights, airplane windows, lenses, bulletproof windows, stop lights, etc. 

Polycarbonate Helmets, hockey masks, bulletproof windows, blinker lights, head lights, etc. 

Polycarbonates are condensation copolymers formed by the reaction of carbonic acid with compounds such as bisphenoi A (Figure 15-31). This reaction forms the polycarbonate termed Lexan. Polycarbonates form clear, tough plastic materials that, if thick enough, can even stop bullets. Consequently, polycarbonate is often used in eye protection, as a scratch-resistant coating for eye glasses, and in bulletproof windows. 

Lexan is a polycarbonate ester condensation polymer that is transparent and nearly unbreakable. It is used in bulletproof windows (a one-inch-thick Lexan plate will stop a. 38-caliber bullet fired from 12 feet), football and motorcycle helmets, and the visors in astronauts helmets. It is made from the two monomers shown below. Draw two repeating units of this polymer. 

Sally follows you into your high-ceilinged office crammed with books and electrical equipment. Lying scattered between the sofa and chairs are three oscilloscopes, a tall Indian rubber plant, and a Rubik s cube. A small blackboard hangs on the wall. The bulletproof, floor-to-ceiling windows give the appearance of a room more spacious than it really is. Sally eyes the electrical hardware. What s all this ... 

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