Flame retardants phosphine oxides

Phosphine Oxides. Development of cyanoethylphosphine oxide flame retardants has been discontinued. Triphenylphosphine oxide [791 -28-6] C gH OP, is disclosed in many patents as a flame retardant, and may find some limited usage as such, in the role of a vapor-phase flame inhibitor. 

APO. Research on ethylenimine [151 -56-4] led to the development of tris(azitidinyl) phosphine oxide [545-55-1] (APO) as a flame retardant for... 

The acid process has three advantages over the alkaline process, ie, (/) higher yield of phosphine (60 vs 25%) (2) more pure gas for use in subsequent reactions (95 vs 40%) and (J) by-product phosphoric acid is relatively valuable and can be sold into a number of markets, eg, in the manufacture of fertilizers and flame retardants. There is no ready outlet for the mixture of phosphites produced via the alkaline route and additional processing by oxidative spray drying is needed to produce phosphates for sale (3). 

Phosphonium salts are typically stable crystalline soHds that have high water solubiUty. Uses include biocides, flame retardants, the phase-transfer catalysts (98). Although their thermal stabiUty is quite high, tertiary phosphines can be obtained from pyrolysis of quaternary phosphonium haUdes. The hydroxides undergo thermal degradation to phosphine oxides as follows ... 

Working with polymethyl methacrylate, Sirdesai and Wilkie (36) have shown that certain phosphine-platinum complexes undergo oxidative insertion reactions and thus catalyze crosslinking leading to flame retardance. This catalyst is expensive and not particularly efficient, but serves as a lead. 

Amino and functional aromatic phosphates, phosphonates, and phosphine oxides have also been used as reactive components to impart flame retardancy to cured epoxy resins. Phosphine oxides are particularly hydrolytically stable and several studies have been reported, for example, of the curing of epoxy resins with bis(aminophenyl) alkyl and aryl phosphine oxides65-67 (Structure 5.19). The relative performances of epoxies cured with aromatic diamine hardeners containing phosphine oxide, phosphinate, phosphonate, or phosphate units have recently been assessed.68 Aromatic phosphine oxides have been functionalized also with maleimide and hydroxyl groups for use as epoxy resin hardeners.69,70... 

A common approach with segmented PUs has been to incorporate a P-containing group (phosphate, phosphonate, phosphine oxide, or phosphazene) into a diol which is then chain-extended with a diisocyanate (e.g., Structures, 5.20 and 5.21).73,74 In one such study,75 phosphonate was found to be a more effective flame retardant than phosphate at the same phosphorus concentration, and in... 

Ren, H., Sun, J., Wu, B., and Zhou, Q., Synthesis and properties of a phosphorus-containing flame retardant epoxy resin based on bisphenoxy(3-hydroxy) phenyl phosphine oxide, Polym. Degrad. Stab., 2007, 92, 956-961. 

Phosphine oxides, phosphonic acids, and phosphinic acids have been found to be flame retardants for various thermoplastic polymers. While there are many reasons for their effectiveness, we postulate that the acidity of the compounds is directly related to their activity and that the formation of polyphosphates (or phosphate glasses) is vital to the mechanism by which they function. 

In this paper we report the use of some phosphine oxides, phosphonic acids, and phosphinic acids to impart fire retardant properties to polymers. In addition, we postulate a mechanism by which these compounds behave as flame retardant agents. 

Dicyclohexylphosphine oxide would thermally disproportionate into dicyclohexylphosphinic acid and dicyclohexylphosphine. We found that both the phosphine oxide, m.p. 72°-75°C., at 15%, and the phosphinic acid, m.p. 144°-145°C., at 5%, in polyethylene are flame retardants. 

Mono- and diphosphonium halides have been found to be flame retardants for plastic materials. Their effectiveness can be related to the formation of various active phosphorus compounds, as well as to many of the postulated mechanisms for flame retardant action. The compounds are postulated to be effective because they decompose on ignition to thermally stable phosphine oxides or phosphonic acids which, in turn, are decomposed to continuous films of phosphate glass. In addition, the phosphonium halides form alkyl halides which cool the flame and/or form halogen acids which are fame retardants. 

Tn the preceding chapter (19) we described the use of phosphine A oxides, phosphonic acids, and phosphinic acids as flame retardants for thermoplastic materials. We also have found phosphonium halides to be effective flame retardants for plastics (5, 6). These compounds were either the monophosphonium halides,... 

The mechanism of action of the phosphonium halides as flame retardants also may be related to the formation of phosphine oxides and/or phosphinic acids from the halide, according to the following reactions (8,14,17). 

Tetrakishydroxymethyl phosphonium chloride (THPC) is well established as a flame retardant agent with textiles (3). Collins (2) has suggested that THPC and urea break down to produce phosphoric acid via a phosphine oxide, phosphinic acid, and phosphonic acid. For cellulose, Collins concludes flameproofing is essentially caused by the dehydrating action of the phosphoric acid formed. 

Use Flame-retarding agent for cotton fabrics. May be used in combination with triethylolamine and urea (Roxel process) or with triethanolamine and tris(l-aziridinyl) phosphine oxide. 

Very interesting new reactive flame retardants were developed by Borissov and Jedlinski [12, 43, 45-50]. A new phosphine oxide polyol is based on tetrakis (hydroxymethyl) phosphonium chloride as 80% aqueous solution. The reactions involved in the synthesis of this phosphine oxide polyol, bis(hydroxymethyl)-N,N-bis(2-hydroxyethyl) aminomethylphosphine oxide [45], are presented below ... 

Bellstein Handbook Reference) AI3-08678 BRN 0878263 CCRIS 876 DImethoxymethyl-phosphIne oxide Dimethyl methanephosphonate Di-methyl methylphosphonate DMMP EINECS 212-062-3 Fyrol DMMP HSDB 2590 Methyl phosphonic acid, dimethyl ester NCI-C54762 NSC 62240 Phosphonic add, methyl-, dimethyl ester Pyrol dmmp. Flame retardant for applications where high phosphorus content, good solvency, and low viscosity are desired lowers viscosity of epoxy resins and unsaturated polyesters filled with hydrated alumina oxide. Liquid bp = 181 , bp20 = 79.6" d ° = 1.4099 Am = 217 nm (e = 13, EtOH) soluble in H2O, Et20, EtOH LDsO (rat orl) > 5000 mg/kg. Akzo Chemie. 

Stackman [29] carried out a study to find systems suitable for reducing the flammability of polyethylene terephthalate (PET) and poly-1,4-butylene terephthalate (PBT) while retaining the chemical and physical properties of the original polymers. The additives used were phosphine oxides, phosphonates and phosphates and their activity was assessed by means of an oxygen index test. Most of the phosphorus esters were found to be volatile under the blending conditions and both the halogenated phosphorus esters and halogenated derivatives of phosphorus oxide proved to be ineffective as flame retardants. 

Isobutyl bis(glycidylpropylether) phosphine oxide [77], oligomeric polyalkyl phosphate polyols [64], triacryloyloxyethyl phosphate (TAEP), diacryloyloxyethyl ethyl phosphate (DAEEP) [80] and phosphate methacrylate [80-82] have all been used to improve the flame retardancy of alkyl phosphate type polymers. 

Isobutyl bis(glycidylpropylether) phosphine oxide has been used as a crosslinking agent for phenolic novolac resin [77] in the production of phosphorus containing novolac-epoxy systems. It was shown that samples containing more than 2% phosphorus content produced a VO material, the industry standard for flame retardancy, bnt phosphorus-free polymers and those containing less than 2% phosphorus were consumed in the first ignition. 

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