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Polycarbonate interfacial polymerization

As with polyesters, the amidation reaction of acid chlorides may be carried out in solution because of the enhanced reactivity of acid chlorides compared with carboxylic acids. A technique known as interfacial polymerization has been employed for the formation of polyamides and other step-growth polymers, including polyesters, polyurethanes, and polycarbonates. In this method the polymerization is carried out at the interface between two immiscible solutions, one of which contains one of the dissolved reactants, while the second monomer is dissolved in the other. Figure 5.7 shows a polyamide film forming at the interface between an aqueous solution of a diamine layered on a solution of a diacid chloride in an organic solvent. In this form interfacial polymerization is part of the standard repertoire of chemical demonstrations. It is sometimes called the nylon rope trick because of the filament of nylon produced by withdrawing the collapsed film. [Pg.307]

Bisphenol A Polycarbonate Resins. These resins are manufactured by interfacial polymerization (84,85). A small amount of resin is produced by melt-polymerization of bisphenol with diphenyl carbonate in Russia and the People s RepubHc of China. Melt technology continues to be developmental in Japan and the West, but no commercial activities have started-up to date, although some were active in the late 1960s. No reports of solvent-based PC manufacture have been received. [Pg.269]

Polycarbonates are manufactured via interfacial polymerization or through a melt esterification process. The properties of polycarbonate can differ greatly based on the method of polymerization. Specifically, the molecular weight distributions created by the two methods differ because of kinetic effects. Polycarbonates manufactured via interfacial polymerization tend to be less stable at high temperatures and less stiff than those produced via melt esterification, unless proper manufacturing precautions are taken. Therefore, when choosing a polycarbonate resin grade for a specific application, it is important to know the method by which it was produced. Either polymerization method can be performed as a continuous or batch process. [Pg.320]

Why is it necessary to cap off the polycarbonate chains with a monofunctional molecule when producing the polymer via interfacial polymerization ... [Pg.324]

What advantages does melt esterification have over interfacial polymerization in manufacturing polycarbonates ... [Pg.324]

What two phases create the interface at which polymerization occurs in interfacial polymerization of polycarbonate ... [Pg.324]

BPF Polycarbonate. The synthesis of bisphenol fluorenone polycarbonate was first reported by Morgan (2). As in that study, the BPF carbonate family reported here was made by an aqueous caustic/organic liquid interfacial polymerization. In our case the monosodium salt of... [Pg.315]

Organic solvents are most commonly used, and encapsulating polymers include ethylcellu-lose, NC, polyvinylidene chloride, polystyrene, polycarbonate, polymethylmethacrylate, polyvinyl acetate and others. Interfacial polymerization produces a polymer such as nylon at the interface between layered solns of two precursor materials such as (in the case of a nylon) a diamine and a diacid (Refs 3 11). If the particle or droplet to be encapsulated is made to pass thru the interface by, say, sedimentation, it will pick up a coating of the polymer as it passes thru... [Pg.143]

This technique can be used effectively to prepare polyesters, polyamides, and polycarbonates. The process of interfacial polymerization can best be illustrated by the reaction between a diamine and a diacid chloride to produce polyamide. The word Nykm is used to represent synthetic polyamides. The various nylons are described by a numbering system that indicates the number of carbon atoms in the monomer chains. Nylons from diamines and dibasic acids are designated by two numbers the first representing the diamine and the second the dibasic acid. Thus, nylon-6,10 is formed by the reaction of hexam-ethylenediamine and sebacoyl chloride ... [Pg.600]

The DMC-based route to aromatic polycarbonates takes place via production of DPC as intermediate and successive melt polymerization between DPC and bisphenol-A, overcoming the previous technology, based on interfacial polymerization with phosgene. [Pg.725]

Standard polycarbonate, (PC), is made from bisphenol A and phosgene via an interfacial polymerization process. The polymer backbone has an aromatic polycarbonate structure with a recurring carbonate, moiety which, uniquely accounts for the outstanding toughness of the polycarbonate and the rigid aromatic unit contributes to its high glass transition temperature. [Pg.1082]

Although aliphatic polycarbonates have been produced, the term polycarbonate usually refers to the bisphenol A esters and copolymers of carbonic acid. Bisphenol A polycarbonate has been made by transesterifying diphenyl carbonate with bisphenol A, but most now is manufactured by interfacial polymerization of bisphenol A with phosgene. [Pg.648]

Pleated sheet conformation, 30,31 PLEDs (polymeric light-emitting diodes), 218 Plexiglas, 62 Plunkett, Roy, 65-66 PMMA. See Poly(methyl methacrylate) Polartec (Polar Fleece), 194 Poly(6-aminohexanoic acid), 25 Poly(a methyl styrene), 20 Polyacetylene, 72, 73 Polyacrylamide, 20 Polyamides, 22, 28, 61, 146 biodegradable, 185 Polyaramids, 77, 86 Polybutadiene, 70,109,148,155 Poly butyl acrylate), 20 Poly(butylene isophthalate), 25 Polycaprolactam, 21 Polycarbonate (PC), 17, 48, 86, 140 biodegradable, 185 density of, 247 impact strength of, 143 permeability of, 163 Polychloroprene, 65 Polycondensation, 85, 90-91 interfacial, 91-92... [Pg.274]

Interfacial polycondensations can also be carried out in vapor-liquid systems. Reaction takes place at the interface between an aqueous solution of a bifunctional active hydrogen compound and the vapor of diacid chloride. Interfacial condensation is commercially important in the synthesis of polycarbonates (1-52). Polymerizations based on diacids are always less expensive than those that use diacid chlorides. In the polycarbonate case, however, the parent reactant, carbonic acid, is not suitable and the derived acid chloride, phosgene (COCI2), must be used. [Pg.183]

Polycarbonates are characterized by the carbonate (-0-COO-) interunit linkage. They may be prepared by interfacial polycondensation of bisphenol A and phosgene in methylene chloride-water mixture. The resulting hydrogen chloride is removed with sodium hydroxide or, in the case of solution polymerization, pyridine is used as the hydrogen chloride scavenger. Polycarbonate may also be made by ester interchange between bisphenol A and diphenyl carbonate. [Pg.443]

The formation of a microcapsule wall through interfacial polycondensation/addition takes place in two steps. First step is the deposit of the oligomer (initial wall) at the oil droplet, and the second step is the wall thickness builds up. As described earlier, the polymerization occurs in oil phase, and the formed initial wall can limit the diffusion of the reactants. This reduces the polymerization rate that has great impact on the surface morphology and thickness of the microcapsule wall. - - Polycondensation by which polyamide, polyester, and polycarbonate microcapsules are prepared can generate acid byproduct during the process therefore, a base is needed to neutralize the acid and drive the reaction to complete. ... [Pg.298]


See other pages where Polycarbonate interfacial polymerization is mentioned: [Pg.283]    [Pg.664]    [Pg.100]    [Pg.97]    [Pg.283]    [Pg.1336]    [Pg.1336]    [Pg.157]    [Pg.497]    [Pg.2277]    [Pg.284]    [Pg.97]    [Pg.277]    [Pg.1823]    [Pg.460]    [Pg.5973]    [Pg.585]    [Pg.498]    [Pg.185]    [Pg.351]    [Pg.92]    [Pg.521]    [Pg.31]    [Pg.39]    [Pg.436]    [Pg.92]    [Pg.62]   
See also in sourсe #XX -- [ Pg.332 , Pg.334 , Pg.336 ]




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