Phosphorus-based acrylics

Anionic polymerization of (meth)acrylates with hindered ester functions can most likely be conducted at room temperature and above to remove the heat of polymerization with low boiling solvents. Polymerization of the important methyl and ethyl (meth)acrylate members of the family, however, are still plagued by chain termination at higher temperatures. The phosphorus based counterions have a stability advantage over tetraalkylammonium counterions which undergo Hoffman elimination. 

It was reported that it is possible to employ persistent phosphorus-based radicals in controUed/Uving free-radical polymerization [283, 284]. Also, in cases of low stability of the hyper coordinated radicals, the ligand exchanges become facile and some organoaluminum, organoboron, and other compounds have been used successfully as transfer agents in polymerizatimi of styrene, acrylics, and vinyl acetate [283, 284]. 

Phosphorus-Based Polymers From Synthesis to Applications aims at providing a broad overview of recent developments in the synthesis and applications of phosphorus-containing polymers. Over the last few years, more and more research papers have been published on this field. Polymerization of different kinds of phosphorus-based monomers using various methods has been carried out (meth)acrylates, (meth)acrylamides, vinylphosphonic acid, styrenic, and allylic monomers. The resulting phosphorus-based materials have found applications in different domains biomedical, complexation with metals, fire retardant additives, fuel cell membranes, etc. 

Scheme 1.1 phosphorus-based (meth)acrylate monomers used for adhesion properties. 

Photopolymerization of phosphorus-based (meth)acrylic monomers was largely investigated for dental applications (Scheme 1.4) 20,21,56 69 monomers bore one or two polymerizable groups and phosphoric acid ester, phosphonate, and phosphonic acid moieties were evaluated. When the phosphorus atom was directly linked to a hydrocarbon chain phosphonate ester), the monomers were more resistant to hydrolysis in comparison with phosphoric acid esters. 

Phosphorus-based (meth)acrylates have been the subject of extensive research in recent years, mainly due to the properties brought by the phosphorus atom, which can be used for different purposes. Most of the prepared monomers are phosphonated esters, whereas only limited numbers of phosphoric esters have been reported in the literature. This can be explained by easier hydrolysis of the latter in comparison with the phosphonate derivatives. Concerning the synthesis methodology, free radical polymerization and photopolymerization have been the most investigated. Some examples... 

Finally, to conclude, it is also important to point out that phosphorus-based poly(meth)acrylates are successfully employed for many applications, including flame retardancy, anticorrosion, and in the biomedical field. As these applications are of great interest, we can assume that the development of other phosphorus-based (meth)acrylate monomers will continue in the future. 

Cellulosic, polyester, and acrylic fibers lubricated with a surfactant-based oiling composition containing an organic phosphorus ester neutralized with an amine showed less pilling, good antistatic properties, and anticorrosiveness. The phosphorus ester salts were hexyl phosphate trimethylamine salt, dodecamethy-lene caproate phosphonate ethylamine salt, and polyethylene glycol dodecyl ether phosphate dimethylamine salt [262]. 

Dichloroethylphosphine has been shown to react with methyl vinyl ketone to form 2-ethyl-5-methyl-A -l,2-oxaphospholen-2-oxide (25), which has been converted to (26) by chlorination in the presence of base. The same phosphine adds to methyl acrylate in the presence of acetic acid to give the phosphine oxide (27). Further examples have appeared of the reactions of the phenylhydrazones of methyl ketones with phosphorus trichloride to produce the heterocycles (28). 

Generally, flame retardants for engineering PET compositions are based on bromine-containing compounds (such as brominated polycarbonate, decabro-modiphenyl oxide, brominated acrylic, brominated polystyrene, etc.). Such compounds are available commercially (such as from the Ethyl Chemical Corporation, Great Lakes Chemical Corporation, Dead Sea Bromine Company, etc.) In addition, the flame-retardant package generally contains a synergist, typically sodium antimonate. PET may also be flame-retarded with diarylphosphonate, melamine cyanurate or red phosphorus. 

The catalyst systems employed are based on molybdenum and phosphorus. They also contain Various additives (oxides of bismuth, antimony, thorium, chromium, copper, zirconium, etc.) and occur in the form of complex phosphomolybdates, or preferably heteropolyacids deposited on an inert support (silicon carbide, a-alumina, diatomaceous earths, titanium dioxide, etc.). This makes them quite different from the catalysts used to produce acrylic acid, which do not offer sufficient activity in this case. With residence times of 2 to 5 s, once-through conversion is better than 90 to 95 per cent, and the molar yield of methacrylic acid is up to 85 to 90 per cent The main by-products formed are acetic add, acetone, acrylic add, CO, C02, etc. The major developments in this area were conducted by Asahi Glass, Daicel, Japan Catalytic Chemical, Japanese Gem, Mitsubishi Rayon, Nippon Kayaku, Standard Oil, Sumitomo Chemical, Toyo Soda, Ube, etc. A number of liquid phase processes, operating at about 30°C, in die presence of a catalyst based on silver or cobalt in alkaline medium, have been developed by ARCO (Atlantic Richfield Co,), Asahi, Sumitomo, Union Carbide, etc. 

SODIUM BICARBONATE (497-19-8) CHNaOj Noncombustible solid. Aqueous solution is a strong base. Violent reaction with acids evolving carbon dioxide. Violent reaction with finely divided aluminum, fluorine, lithium. Incompatible with organic anhydrides, acrylates, alcohols, aldehydes, alkylene oxides, substituted allyls, cellulose nitrate, cresols, caprolactam solution, epichlorohydrin, ethylene dichloride, isocyanates, ketones, glycols, nitrates, phenols, phosphorus pentoxide, 2,4,6-trinitrotoluene. Forms explosive material with 2,4,5-trinitrotoluene and increases the thermal sensitivity of 2,4,6-trinitrotoluene (TNT) by decreasing the tenqjerature of explosion from 566°F/297°C to 424°F/218°C. Attacks metals. Thermal decomposition at 228°F/109°C, releasing oxides of carbon. 

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