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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 ...
The type I reaction dominates, which cause chain scission at the carbonyl unit to give a range of products. [1] [38] Type II Norrish reactions are less common but give rise to acetaldehyde by way of vinyl alcohol esters. [36] This has an exceedingly low odour and taste threshold and can cause an off-taste in bottled water. [39]
For example, in water the hydrophobic blocks of a copolymer could end up on the inside of a micelle, with hydrophilic blocks on the outside. [4] Additionally, a change in pH could cause micelles to swap their inner and outer molecules depending on the properties of the polymers involved.
The reaction of BPA with phosphorus oxychloride and phenol forms BADP, which is used as a liquid flame retarder in some high performance polymer blends such as polycarbonate/ABS mixtures that are used to form the casings for household electronics.
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 .
There are two examples each for liquid-liquid and liquid-in-liquid emulsion, either using one monomer or two. The most commonly used interfacial polymerization methods fall into 3 broad types of interfaces: liquid-solid interfaces, liquid-liquid interfaces, and liquid-in-liquid emulsion interfaces. [ 1 ]
One important class of condensation polymers are polyamides. [4] They arise from the reaction of carboxylic acid and an amine. Examples include nylons and proteins.When prepared from amino-carboxylic acids, e.g. amino acids, the stoichiometry of the polymerization includes co-formation of water:
The kinetics and thermodynamics of this reaction are not favorable. For example, at higher temperatures, dimethyl carbonate undesirably methylates phenol to give anisole . [ 2 ] Despite this, diphenyl carbonate made from non-phosgene sources has become a widely used raw material for the synthesis of bisphenol-A -polycarbonate in a melt ...