Polycarbonate (PC) Resins
Polycarbonate resins are engineering thermoplastics. They are long-chain linear polyesters of carbonic acid and dihydric phenols, such as bisphenol A (BPA). They are produced by reacting bisphenol A with phosgene. Caustic soda is used in the polycondensation process to make polycarbonate resins. Caustic soda is used to dissolve BPA and small quantities of chain terminator. Phosgene, which is dissolved in methylene chloride, reacts with BPA to form polycarbonate. Upon completion, the aqueous phase is removed, and the organic phase is washed with caustic soda and hydrogen chloride (HCl).
Polycarbonate resins are typically characterized by high-impact strength, dimensional stability, excellent transparency, and good electrical properties. In addition to general-purpose polycarbonate resins, a variety of specialty materials, such as blends and alloys, are also available. Polycarbonates are widely used with applications in the automotive industry, glazing, electronics, computers and business machines. For example, optical media (audio CD, software CD, DVD, and Blu-ray) are made from high-purity polycarbonates. Other examples of consumer applications of polycarbonates are luggage, furniture, juicers and blenders.
The properties of polycarbonates, their strength and remarkable transparency, in combination with their biocompatibility, make them ideal materials for medical appliances such as dialysis machines and oxygenators. The polycarbonate can be sterilized with epoxyethane, radiation, or steam.