Ethyl Corporation

Matthew K Juneau

J Robert Adams, Jr

James R Mitrano

Gerald M Sulzer

Joseph B Tedder, Jr

Cyclic phosphonitrilic halide trimer is made in high yield and at a rapid rate by adding NH.sub.3 or ammonium halide to a pyridine-hydrogen halide complex and adding phosphorus pentahalide and a solvent for the trimer (e.g. monochlorobenzene) and heating the mixture to above 90.degree. C. to form trimer which dissolves in the solvent and then separating the trimer-solvent phase from the residue phase of pyridine-hydrogen halide complex and recovering trimer from the solvent phase and recycling the pyridine-hydrogen halide phase to a subsequent procedure conducted in the same manner. The process can also be adapted to produce linear species in high yield also.

Cyclic phosphonitrilic halide process

Polymer-grade cyclic phosphonitrilic chloride trimer can be obtained from crude cyclic polyphosphonitrilic chlorides by forming a solution of the crude cyclics, water washing the solution, distilling solvent to form a hot concentrate, cooling to form a precipitate and distilling the precipitate to form polymer-grade trimer.

Phosphonitrilic chloride trimer purification

Cyclic phosphonitrilic chloride trimer suitable for polymerization to light colored, high molecular weight, linear polyphosphonitrilic chloride can be made by (1) reacting PCl.sub.5 and NH.sub.4 Cl in an inert solvent (e.g. monochlorobenzene) to form a solution of a low molecular weight linear and cyclophosphonitrilic chlorides, (2) evaporating solvent to form a concentrate, (3) adding water and cooling the mixture to precipitate cyclic trimer, (4) separation of the trimer precipitate and (5) distillation of the separated trimer.

Phosphazene trimer purification

Residual alkali metal salt (e.g. NaCl) is removed from an alkali metal alkoxide and/or aryloxide-polyphosphonitrilic halide reaction product by neutralizing the reaction solution with acid and water extracting the salt using a lower water-soluble alcohol (isopropanol) to effect rapid phase separation.

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Baton Rouge, LA, United States of America

Matthew K Juneau