Mixed esters of polyphosphazenes

摘要

A polyphosphazene hydraulic fluid that remains solids-free on storage at temperatures down to -30 DEG C. over an extended period can be made by reacting a solution of sodium phenoxide, sodium m-methylphenoxide, sodium p-methylphenoxide and sodium trifluoroethoxide with a small stoichiometric excess of cyclic phosphonitrilic chloride oligomer, mainly trimer, and then reacting the remaining replaceable chlorine atoms with a solution of sodium trifluoroethoxide.