![]() The cyclohexane is used as a comonomer to suppress crystallisation tendency of the BPA-derived product. 1,1-bis(4-hydroxyphenyl)cyclohexane and dihydroxybenzophenone. Many other diols have been tested in place of bisphenol A, e.g. In this way, approximately one billion kilograms of polycarbonate is produced annually. Na 2(OC 6H 4) 2CMe 2 + COCl 2 → 1/n n + 2 NaCl ![]() The net reaction from the diphenoxide is: The di phenoxide (Na 2(OC 6H 4) 2CMe 2) reacts with phosgene to give a chloroformate, which subsequently is attacked by another phenoxide. The first step of the synthesis involves treatment of bisphenol A with sodium hydroxide, which deprotonates the hydroxyl groups of the bisphenol A. The overall reaction can be written as follows: The main polycarbonate material is produced by the reaction of bisphenol A (BPA) and phosgene COClĢ. A balance of useful features, including temperature resistance, impact resistance and optical properties, positions polycarbonates between commodity plastics and engineering plastics. ![]() Polycarbonates received their name because they are polymers containing carbonate groups (−O−(C=O)−O−). The unique O=C bond is short (1.173 Å in the depicted example), while the C-O bonds are more ether-like (the bond distances of 1.326 Å for the example depicted). This molecule reflects a subunit of a typical polycarbonate derived from bis(phenol-A).Ĭarbonate esters have planar OC(OC) 2 cores, which confers rigidity. Structure of dicarbonate (PhOC(O)OC 6H 4 ) 2CMe 2 derived from bis(phenol-A) and two equivalents of phenol. Products made from polycarbonate can contain the precursor monomer bisphenol A (BPA). Polycarbonates do not have a unique resin identification code (RIC) and are identified as "Other", 7 on the RIC list. ![]() Because of these properties, polycarbonates find many applications. ![]() They are easily worked, molded, and thermoformed. Polycarbonates used in engineering are strong, tough materials, and some grades are optically transparent. Polycarbonates ( PC) are a group of thermoplastic polymers containing carbonate groups in their chemical structures. ![]()
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