Polycarbonate
Polycarbonates are a particular group of polymers that are moldable under heat; as such, these plastics are very widely used in modern manufacturing.
Polycarbonate is a very durable material, and can be laminated to make bullet-proof glass, though “bullet-resistant” would be more accurate. Polycarbonate is becoming more common in housewares. Other products made from polycarbonate include sunglass lenses and compact discs.
LEXAN® is the registered trademark for polycarbonate plastic manufactured by General Electric. MERLON® is the registered trademark used by the Mobay Chemical Company.
Synthesis
Polycarbonate can be synthesized from bisphenol A and phosgene. The first step in the synthesis of polycarbonate from bisphenol A is treatment of bisphenol A with sodium hydroxide. This deprotonates the hydroxyl groups of the bisphenol A molecule. The deprotonated oxygen reacts with phosgene through a back-side attack to create a tetrahedral intermediate followed by elimination of a chloride ion as a leaving group to form a chloroformate. The chloroformate is then attacked by another deprotonated bisphenol A, eliminating the remaining chloride ion and forming a dimer of bisphenol A with carbonate linkage. Repetition of this process yields polycarbonates. Polycarbonate is also widely known for it is a major material that makes up the popular Nalgene Bottles.