The present invention relates to compounds of formula I, which are unsymmetrical aromatic ether diacids, and polymers formed from the same. [R′—(Y)p—O]q—Ar—[O—(X)r—R′]s   I Polymers formed from the functionalized unsymmetrical aromatic ether diacids are expected to have controllable degradation profiles, enabling them to release an active component over a desired time range. The polymers are also expected to be useful in a variety of medical applications.