Atochem

Societe Nationale Elf Aquitaine

Guy Pagniez

Philippe Potin

Roger De Jaeger

Nadine Passimourt

Roger DeJaeger

Ghislaine D'Halluin

Serge Bordere

The sodium fluoroalcoholates are prepared under conditions resulting in neither reactant nor final product degradation, by (a) reacting, under reflux, the corresponding fluoroalcohols, e.g., the mono-, di- or trifluoroethanols, with sodium methanolate in the presence of a solvent having a boiling point higher than that of methanol and/or a solvent which forms an azeotrope with methanol, and (b) selectively trapping the methanol of reaction, e.g., in a molecular sieve, as it is released into the vapors which evolve upon refluxing the step (a) reaction mixture; the sodium fluoroalcoholates thus produced are well suited for direct reaction with polydichlorophosphazenes.

Preparation of sodium fluoroalcoholates

The molecular weights of the poly(dichlorophosphazenes), and of the poly(organophosphazenes) produced therefrom, are controlledly regulated by heating such poly(dichlorophosphazenes) in the presence of an effective molecular weight-regulating amount of phosphorus oxychloride.

Poly(dichlorophosphazenes)/poly(organophosphazenes) having regulated

The polycondensation disrupting effects of the impurities in an impure N-dichlorophosphoryltrichlorophosphazene, P.sub.2 NOCl.sub.5, or oligomer thereof, are avoided by polycondensing such impure P.sub.2 NOCl.sub.5 into a high molecular weight uncrosslinked poly(dichlorophosphazene) in the presence of an effective impurity-inhibiting, polymerization-controlling amount of phosphorous pentachloride, PCl.sub.5.

Polycondensation of impure P.sub.2 NOCl.sub.5 into uncrosslinked

Essentially pure and colorless N-(dichlorophosphoryl)trichlorophosphazene [P.sub.2 NOCl.sub.5 ] is prepared/purified under relatively moderate conditions, by reacting phosphorous pentachloride with ammonium chloride, treating the resulting medium of reaction, containing P.sub.3 NCl.sub.12, with SO.sub.2, and thin film evaporating the medium of reaction, advantageously in two stages, to eliminate SO.sub.2, POCl.sub.3 and SOCl.sub.2 values therefrom.

Essentially pure/colorless P.sub.2 NOCl.sub.5

Crude polyorganophosphazenes, produced by the nucleophilic cosubstitution of polydichlorophosphazenes and contained in a reaction medium which includes such polyorganophosphazenes, reaction solvent for the cosubstitution reaction, excess nucleophilic reagent and/or product of neutralization thereof, and, when present, any alkali metal salts of neutralization, are efficiently and facilely purified, in a single treatment zone, advantageously under agitation in a discontinuous malaxator, by both eliminating the reaction solvent and thereafter washing the resulting reaction medium with a liquid which is a nonsolvent for the polyorganophosphazenes, but miscible with the other products present in said reaction medium.

Purification of crude polyorganophosphazenes

Linear polychlorophosphazenes are more rapidly produced by polycondensing N-(dichlorophosphoryl)trichlorophosphazene [P.sub.2 NOCl.sub.5 ] in the presence of a catalytically effective amount of the bis(dichlorophosphoryl)imide of the formula: ##STR1##

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Poey de Lescar, France

Guy Pagniez