Polycarbonates (PCs) are thermoplastic polymers containing the carbonate moiety (-O-(C=O)-O-) in its monomeric structure. They are unusually tough yet malleable and almost as transparent as glass. Their impact strength is significantly higher compared to other types of plastic.
Physical and Chemical Properties
Almost completely transparent in its raw state, polycarbonate transmits visible light very effectively. As a protective material, it is durable, safe and completely heat and shatter-resistant. Polycarbonate is not easily cracked or broken, even under pressure of plastic deformation. It has a melting point of 155°C and can be reheated and cooled without degrading. Polycarbonate is lightweight and durable enough to be of interest to the architecture and transportation industries, and it is thermally stable, making it a very useful and hygienic cleaning tool, particularly at high temperatures. Polycarbonate insulates electricity and can make an efficient dielectric when used in a high-stability capacitor.
Production and Processing
To make polycarbonate resins, hydrocarbon fuels are distilled into fraction which then undergo polymerization or polycondensation. The most common process uses condensation polymerization between BPA (bisphenol-A) and diphenyl carbonate or carbonyl chloride. The resulting polycarbonate resins are transformed into finished materials using either injection molding, structural foam molding, blow molding, extrusion or vacuum forming. The end products are glazing and roofing sheets, lenses, optical equipment, IT components, medical device parts and food and hygiene articles.
Polycarbonate is abundant in the packaging world, forming tableware, containers and transparent bottles, among other tough plastic products. Data storage devices such as DVDs and CDs are made from injection-molded polycarbonate. Household appliances use polycarbonate components and many electronic devices and chargers contain polycarbonate housings. In the automotive industry, polycarbonate forms vehicle headlamps, dashboards, mirror housings and turn signals. Additionally, bullet-resistant windows are produced with polycarbonate. Other miscellaneous uses include greenhouse sheeting, glazing, safety goggles and lightweight luggage.