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The main polycarbonate material is produced by the reaction of bisphenol A (BPA) and phosgene COCl 2. The overall reaction can be written as follows: The first step of the synthesis involves treatment of bisphenol A with sodium hydroxide, which deprotonates the hydroxyl groups of the bisphenol A. [6] (HOC 6 H 4) 2 CMe 2 + 2 NaOH → Na 2 (OC 6 ...
A polycarbonate is an oxocarbon dianion consisting of a chain of carbonate units, where successive carbonyl groups are directly linked to each other by shared additional oxygen atoms. That is, they are the conjugate bases of polycarbonic acids , the conceptual anhydrides of carbonic acid , or polymers of carbon dioxide .
The degradation chemistry is complicated due to simultaneous photodissociation (i.e. not involving oxygen) and photo-oxidation reactions of both the aromatic and aliphatic parts of the molecule. Chain scission is the dominant process, with chain branching and the formation of coloured impurities being less common.
It can be thought of chemically as the double acyl chloride analog of carbonic acid, or structurally as formaldehyde with the hydrogen atoms replaced by chlorine atoms. In 2013, about 75–80 % of global phosgene was consumed for isocyanates , 18% for polycarbonates and about 5% for other fine chemicals .
Hydrogen gas released in this way can be used as hydrogen fuel, but must be kept apart from the oxygen as the mixture would be extremely explosive. Separately pressurised into convenient 'tanks' or 'gas bottles', hydrogen can be used for oxyhydrogen welding and other applications, as the hydrogen / oxygen flame can reach approximately 2,800°C.
In the diagram, M x refers to the original monomer molecule or any of many dissociation products such as chlorine, fluorine and hydrogen. The M• species refers to those that are activated and capable of participating in reactions to form new covalent bonds. The •M• species refers to an activated difunctional monomer species.
Because this reaction is highly exothermic (238 kJ/mol), the temperature is monitored, to guard against thermal degradation of the catalyst. The reaction is as follows: CH 2 =CH 2 + 2 CuCl 2 → 2 CuCl + ClH 2 C-CH 2 Cl. The copper(II) chloride is regenerated by sequential reactions of the cuprous chloride with oxygen and then hydrogen chloride:
The simplified chemical reaction is: NaCl + H 2 O + energy → NaOCl + H 2 [citation needed] That is, energy is added to sodium chloride (table salt) in water, producing sodium hypochlorite and hydrogen gas. Because the reaction takes place in an unpartitioned cell and NaOH is present in the same solution as the Cl 2: 2 NaCl + 2 H 2 O → 2 ...