polycarbonates


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polycarbonates,

group of clear, thermoplastic polymerspolymer
, chemical compound with high molecular weight consisting of a number of structural units linked together by covalent bonds (see chemical bond). The simple molecules that may become structural units are themselves called monomers; two monomers combine to form a dimer,
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 used mainly as molding compounds (see plasticplastic,
any organic material with the ability to flow into a desired shape when heat and pressure are applied to it and to retain the shape when they are withdrawn. Composition and Types of Plastic
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). Polycarbonates are prepared by the reaction of an aromatic difunctional phenol with either phosgene or an aromatic or aliphatic carbonate. The commercially important polycarbonates use 2,2-bis (4-hydroxyphenol)-propane (bisphenol A) and diphenyl carbonate. This polymer is a clear plastic with a slight yellow discoloration. It has excellent electrical properties and a high impact strength.
References in periodicals archive ?
Michelle Jou, Global Head of Covestros Polycarbonates segment, said, There is a rapidly growing demand for polycarbonate resins and blends, in particular in China.
USPRwire, Tue Apr 07 2015] North America Polycarbonate Market by Applications (Automotive, Consumer, Electrical & Electronic, Medical, Optical Media, Packaging & Sheet & Film) & Geography - Trends & Forecasts to 2019
In consumer goods markets, there are countless applications for clear plastics such as copolyesters, acrylic, SAN, amorphous nylon, and polycarbonate.
Bisphenol A, a building block of polycarbonate plastics, can mimic the effects of the body's natural estrogens (SN: 7/3/93, p.
Various concentrations of glass-fiber reinforcements have also been added to polycarbonates.
On the demand side, exporters and strategic planners focusing on polycarbonates, alkyd resins, and other polyesters in primary forms in France face a number of questions.
During the inauguration celebration, Michelle Jou, Head of the Polycarbonates segment at Covestro, said: In Asia and especially China, the demand for polycarbonates and solutions based on it is growing in important industries like electronics, healthcare and automotive.
Three new or improved polycarbonate resins for optical discs were introduced by GE Plastics, Pittsfield, Mass.
His team recently gained one such insight while examining the molecular structure of polycarbonate, a material serendipitously discovered in the 1950s and long ranked as the toughest polymer, Yee says.
Because polycarbonates are widely traded, the ITP Indicator is also a unique gauge of global demand growth because, as demand increases or decreases, it is generally reflected in an increase or decrease in global trade.
As part of the worldwide consolidation of its business with sheets made of the high-performance plastic polycarbonate, Bayer MaterialScience has decided to close its site in Darmstadt, Germany.
They are also useful as processing and mold-release lubricants for such polymers as ABS, polyesters, polycarbonates, nylons, polybutylenes and PE.