Polyphosphazene polymers are prepared which contain repeating units represented by the formulas: ##STR1## wherein X and X' are the same or different and are represented by: ##STR2## wherein R is selected from the group consisting of hydrogen and unsubstituted and substituted alkyl, aryl, and heterocyclic groups; X' may additionally be selected from the group consisting of chloro- and substituted or unsubstituted alkoxy, aryloxy, amino and mercapto radicals or a mixture thereof; and 20.ltoreq.(w+y+z).ltoreq.50,000.The polymers of the invention can be utilized in applications such as molding, coatings, foams and the like.