Polycarbonate

Description

A group of thermoplastic polymers containing carbonate groups (O-CO-O) in their chemical structures. Polycarbonates are strong, tough, durable materials that can be easily worked and molded. These optically transparent plastics have a high impact resistant along with low scratch resistance and can be used as replacements or laminates for glass windows to increase their strength. They are commonly found in eyewear lenses, automobile windshields and safety glass panels. Additionally, polycarbonates do not conduct electricity and are heat-resistant, which makes them ideal as insulators and capacitors.

Polycarbonates were first discovered in 1898 in Munich but not commercialized until 1953 by Bayer using the name Makrolon. At the same time, GE began production of Lexan. The term 'polycarbonate' is used solely for the polymer produced from bisphenol A and phosgene.

Synonyms and Related Terms

Brand Names: Makrolon (Bayer); Lexan (General Electric)

Applications

• Transparent tubes and rods
• Transparent films and sheets
• Flat and curved glazing
• Safety glass, Compact discs, DVDs
• Sign and display boards as well as protective coverings
• May be used for 3D printing

Personal Risks

Bleach (sodium hypochlorite) and alkali cleaners catalyze the release of bisphenol A (BPA) from polycarbonate (Hunt 2003, Koehler 2003).

Collection Risks

Standard resins alone are not suitable for long-term exposure to UV radiation. They will yellow with long exposure to sunlight.

Environmental Risks

• It is listed as “other” or “7” on the resin identification code (RIC) list
• Polycarbonate can form bisphenol A (BPA) in the environment. It is on the watch list of many countries including the United States and Germany. Bisphenol A does not break down in landfills.
• Thermal degradation polycarbonates produce phenol and phenol derivatives, known environmental pollutants (Collin 2012, Pollution Database 2017)

Physical and Chemical Properties

• Resistant to dilute acids, alcohol and halogenated hydrocarbons.
• Affected by concentrated acids, alkalis, aromatic solvents, and ketone
• Tg = 147 c
• Density = 1.2 g/ml
• Refractive index = 1.584-1.586

Working Properties

Can be folded/bent using sheet metal techniques.

Resources and Citations

• Wikipedia: Polycarbonate Accessed Nov. 2024
• Omnexus: Guide on PC
• Contributions: Molly McGath, AIC Plastics Panel, 2020.
• Hunt, PA; Kara E. Koehler; Martha Susiarjo; Craig A. Hodges; Arlene Ilagan; Robert C. Voigt; Sally Thomas; Brian F. Thomas; Terry J. Hassold (2003). "Bisphenol A Exposure Causes Meiotic Aneuploidy in the Female Mouse". Current Biology. 13 (7): 546–553. doi:10.1016/S0960-9822(03)00189-1. PMID 12676084
• Koehler, KE; Robert C. Voigt; Sally Thomas; Bruce Lamb; Cheryl Urban; Terry Hassold; Patricia A. Hunt (2003). "When disaster strikes: rethinking caging materials". Lab Animal. 32 (4): 24–27. doi:10.1038/laban0403-24. PMID 19753748. Archived from the original on 2009-07-06. Retrieved 2008-05-06.
• Collin, S.; Bussière, P. -O.; Thérias, S.; Lambert, J. -M.; Perdereau, J.; Gardette, J. -L. (2012-11-01). "Physicochemical and mechanical impacts of photo-ageing on bisphenol a polycarbonate". Polymer Degradation and Stability. 97 (11): 2284–2293. doi:10.1016/j.polymdegradstab.2012.07.036.
• "Pollution Database". pollution.unibuc.ro. Archived from the original on 2017-12-29. Retrieved 2016-11-14.