Fluorocarbons polymeric

The reason for Nafion LB-film fabrication was the wish to obtain the highly ordered systems from perfluorinated ion exchange polymer with multilayered structure, where the ionic layers (conductors) would alternate with fluorocarbon polymer layers (insulators), and to investigate the properties of such films.74 This polymer contains a hydrophobic fluorocarbon polymeric chain and hydrophilic ionic groups, so it is sufficiently amphiphilic it has a comblike structure that makes it a suitable polymer for LB-film deposition. 

Laschewsky A, Ringsdorf H and Schmidt G 1985 Polymerization of hydroxocarbon and fluorocarbon amphiphiles in Langmuir-Blodgett multilayers Thin Soiid Fiims 134 153-72... 

Figure C2.13.7. Change between polymerizing and etching conditions in a fluorocarbon plasma as detennined by tire fluorine-to-carbon ratio of chemically reactive species and tire bias voltage applied to tire substrate surface [36].

Hydrocarbon Polymers. It is difficult to produce perfluorocarbon polymers by the usual methods. Many monomers, such as hexafluoropropylene, polymerize only slowly because of the steric hindrance of fluorine. Furthermore, some monomers are not very stable and are difficult to synthesize. Direct fluorination can be used for the direct synthesis of fluorocarbon polymers (68—70) and for producing fluorocarbon coatings on the surfaces of hydrocarbon polymers (8,29,44—47,49,68—71). 

The breadth of reactions catalyzed by cobalt compounds is large. Some types of reactions are hydrotreating petroleum (qv), hydrogenation, dehydrogenation, hydrodenitrification, hydrodesulfurization, selective oxidations, ammonoxidations, complete oxidations, hydroformylations, polymerizations, selective decompositions, ammonia (qv) synthesis, and fluorocarbon synthesis (see Fluorine compounds, organic). 

Interesting TPEs can be derived from binary and ternary blends of polyfunctional acrylates, ACM, and fluorocarbon rubber (FKM) [53]. During the blend preparation, the liquid multifunctional acrylate monomer used is polymerized and forms the continuous matrix encapsulating the... 

Williams, R. C., Vasta-Russell, J. F., Glajch, J. L., and Golebiowski, K., Separation of proteins on a polymeric fluorocarbon high-performance liquid chromatography packing, /. Chromatogr., 371, 63, 1986. 

It should be emphasized that the electrochemical carbonization proceeds, in contrast to all other common carbonization reactions (pyrolysis), already at the room temperature. This fact elucidates various surprising physicochemical properties of electrochemical carbon, such as extreme chemical reactivity and adsorption capacity, time-dependent electronic conductivity and optical spectra, as well as its very peculiar structure which actually matches the structure of the starting fluorocarbon chain. The electrochemical carbon is, therefore, obtained primarily in the form of linear polymeric carbon chains (polycumulene, polyyne), generally termed carbyne. This can be schematically depicted by the reaction ... 

Kay, E., Cobum, J. and Dilks, A. Plasma Chemistry of Fluorocarbons as Related to Plasma Etching and Plasma Polymerization. 94, 1-42 (1980). 

J.X. Tang, Y.Q. Li, L.R. Zheng, and L.S. Hung, Anode-organic interface modification by plasma polymerized fluorocarbon films, J. Appl. Phys., 95 4397-4403 (2004). 

Both hydrocarbon and fluorocarbon organic peroxides were used to initiate polymerization. The half-lives of several that were used are shown in Table 6.3. The perfluoro-organic peroxides were prepared at temperatures below 0°C by the reaction of the corresponding acyl chloride and sodium peroxide (Scheme 2). Sodium peroxide was formed from an aqueous mixture of sodium hydroxide and hydrogen peroxide. 

Scheme 1. Free radical polymerization of fluorocarbon acrylates in supercritical C02.

The best known aspect, and the first one to find commercialization in the direct fluorination area, was the fluorination of polymer surfaces. This Lagow-Margrave invention, trademarked Fluorokote, involved many types of polymeric materials in various forms e.g., polyethylene bottles, polypropylene objects, and rubber gloves. Polyethylene bottles are easily given fluorocarbon surfaces (>0.1 mm), and this has been commercialized. Air Products has at least 20 licenses for what is known as their Aeropak process and Union Carbide has a Linde Fluorination process as well. Applications in chemical, pharmaceutical, and cosmetic storage are widespread. 

A new method for the syntheses of fluorocarbon polyarylate polymers has been demonstrated. The chemistry utilizes the [2jt+2rr] cyclodimerization of fluorinated olefins and generates polymers of novel composition. The first generation of polymers prepared by this method are polyarylate homopolymers. Theremoplastic polymers of high molecular weight can be achieved via neat or solution polymerization. One example of a thermoset polymer prepared by this method has a high Tg, low dielectric constant and dissipation factor, low moisture... 

The fluorocarbons are resistant to the action of strong acids and aqueous alkalis they are non-inflammable and attacked only by such reagents as fused caustic alkalis. The plastic teflon is polymerized C2F4 (cf. polythene which is polymerized C2H4) and is made into tubing, or into sheets to act as linings for vessels required to withstand corrosion. The liquid fluorocarbons ( fluorolubes ) are used where hydrocarbon oils would be attacked, and their non-inflammability makes them particularly useful. 

Figure 10, Schematic of the influence of fluorine to carbon ratio and electrode bias on etching versus polymerization processes in fluorocarbon plasmas, (Reproduced with permission from Ref, 40 J...

K. Stabler, J. Selb, F. Candau, Multicompartment polymeric micelles based on hydrocarbon and fluorocarbon polymerizable surfactants, Langmuir 15 (1999) 7565-7576. 

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