4 Polycarbonate.

The modern era of engineering thermoplastics was launched in 1953 when Dr. Hermann Schnell of Bayer AG in Germany and Dr. Daniel W. Fox of GE Plastics in Pittsfield, Mass., independently discovered the versatile engineering resin called polycarbonate.

Fox was conducting a series of experiments while working to develop a new wire insulation material when he found himself with a transparent substance that hardened in a beaker. That marked the beginning of GE's Lexan polycarbonate business. Schnell discovered polycarbonate while working on aromatic derivatives at Bayer's main lab in Uerdingen, Germany. As result, the company's Makrolon PC business was born. Both companies began to commercially produce PC in 1958. (It was first reported in the New Materials section of PLASTICS TECHNOLOGY in December of that year.)

The first commercial production of bisphenol-A (BPA), an important feedstock for PC, was a turning point. BPA was first made for epoxy resins but its reaction with phosgene made commercial production of PC possible.

Polycarbonate today is one of the most widely used engineering thermoplastics in the world. It has found extensive use in business equipment, automobiles, and telecommunications products. Polycarbonate was first used for electrical and electronic applications such as distributor and fuse-box covers and later was extruded into sheet and used as glazing for greenhouses and other architectural applications. In the 1980s, polycarbonate's clarity, light weight, and impact resistance made it the ideal replacement for glass in automotive headlamps. For car makers, the use of PC brought vast new potential for front-end design.

Another breakthrough application came in 1982 with the introduction of the compact disc with PC as the substrate. Other major applications include 5-gal water bottles, cell phones, eyeglass lenses, DVDs, and bullet-proof glazing. Today, the PC market is growing about 8% annually and total global consumption is about 5.4 billion lb/yr.