Process for preparing polyphosphazene polymers containing fluoroalkoxy and/or aryloxy substituents

A method of preparing polyphosphazene polymers containing from 20 to 50,000 units represented by the formulae:

• ##STR4## wherein R and R' are the same or different and are organic radicals selected from the group consisting of fluoroalkyl groups and substituted or unsubstituted aryl groups, said method comprising the steps of:
• (a) reacting a fluoroaliphatic alcohol or substituted or unsubstituted aromatic alcohol or mixture of said alcohols with sodium hydroxide in an organic solvent or mixture of organic solvents which will form an azeotrope with water produced by the reaction;
• (b) removing water produced by the reaction of said alcohols or mixture of alcohols and said sodium hydroxide from the reaction zone by azeotropic distillation thereby producing substantially dry sodium salts of said alcohols;
• and
• (c) reacting said substantially dry sodium salts of said alcohols with a linear polydichlorophosphazene polymer represented by the formula (NPCl.sub.2).sub.n, in which n is from 20 to 50,000.