polycarbonate

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polycarbonate

[¦päl·i′kär·bə·nət]
(organic chemistry)
[OC6H4C(CH3)2C6H4OCO]x A linear polymer of carbonic acid which is a thermoplastic synthetic resin made from bisphenol and phosgene; used in emulsion coatings with glass fiber reinforcement.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Polycarbonate

 

a polyester of carbonic acid and dihydroxy compounds of the following general formula:

Polycarbonates may be aliphatic, mixed, or aromatic, depending on the nature of A and A′. Only aromatic polycarbonates have gained practical importance; they are produced commercially by interphase polycondensation, phosgenation of aromatic dihydroxy compounds in a pyridine medium, or transesterification of diaryl carbonates (for example, diphenylcarbonate) by aromatic dihydroxy compounds. The most commonly used dihydroxy compound is 4,4′ -isopropylidenediphenyl, also called dian or bisphenol A. Polycarbonates based on the bisphenol A have the formula

These polycarbonates are thermoplastic linear polymers (molecular weight, 35,000–70,000) that are characterized by very high impact strength (250–500 kilojoules per sq m, or kilograms-force per cm per sq cm [kgf.cm/cm2]), yield strength (strength in flexure, 77–120 meganewtons per sq m [MN/m2], or 770–1,200 kgf/cm2), and very good dielectric properties (dissipation factor, 0.0009 at 50 hertz). Polycarbonates are optically transparent, cold-resistant (stable at temperatures slightly below – 100°C), and self-extinguishing; they dissolve in most organic solvents such as methylene chloride and chloroform, and are resistant to acids, salt solutions, and oxidizing agents.

Polycarbonates are processed by all the standard methods used for thermoplastic resins (for example, injection molding, extrusion, and compression molding). They are used in the preparation of films, fibers, and various products in many sectors of industry, mainly in electric engineering. In 1973, world production of polycarbonates (mainly in the Federal Republic of Germany, the USA, and Japan) was 100,000 tons.

REFERENCES

See references under .

O. V. SMIRNOVA

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

polycarbonate

A category of plastic materials used to make myriad products, including CDs and DVDs.
Copyright © 1981-2019 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
References in periodicals archive ?
Makrolon WG, "None Tougher," polycarbonate sheet offers high impact strength and high modulus of elasticity.
As envisioned, the technology will allow customers running the musical spectrum to colorize their Makrolon PC-made CDs and DVDs.
The glass-like clarity of Makrolon 2458 polycarbonate makes an entirely transparent shell that enables clear observation of the proper functioning of the oxygenating process.
Like all Makrolon products the new multi UV 3/16-20 series is impact-resistant and stands out for being application-friendly.
Bayer Materi-alScience's Makrolon MAK clear polycarbonate will be used at the workstations, allowing natural light to filter throughout the workplace.
Creating a high-quality diffuser package begins with selecting a Makrolon polycarbonate resin grade best suited to the particular application.
The i-mode is the first vehicle to feature the new BayVision glazing system and Collimator headlight lenses made from a company called Makrolon. The advanced entertainment system was developed by LG electronics.
Makrolon windows protect the forward-facing LED lamps and rear-facing IR lamp; a scratch-resistant sapphire window protects the rear-viewing camera.
The Audio CD: the Initial Spark that Set off Optical Data Storage For the last quarter of a century the primary substrate material for CDs has been polycarbonate, such as high-tech Makrolon polycarbonate from Bayer.