A series of polymers based on the reaction products of bis-(a-chloro-ptolyl)ether, formaldehyde, and phenols have been synthesized. The char yields of these polymers, determined by thermogravimetric analysis, vary between 50 and 66%. The data indicate that char yield is influenced by the degree of cross-linking and that the char structure still possesses the phenyl ether unit. Incorporation of thermally stable fillers or substituents on the phenol can produce desired properties without weakening the polymer system. The high char yield and char stability of these polymer systems suggest potential merits in ablative applications.