Synthesis an characterization of polyanhydrides containing amido groups

Abstract 4,4′‐Alkane‐ and oxaalkanedioyldiiminodibenzoic acids ( 3a–e ) were prepared from 4‐aminobenzoic acid and various alkanedioyl and oxaalkanedioyl chlorides ( 2a–e ). A series of polyanhydrides having both hydrolytically labile anhydride linkages and anilide units ( 4a–k ) was prepared by polycondensation of the diacids 3a–k at 150–170°C via acetic mixed anhydrides, using different methods. Molecular weights, glass transition temperatures, and solubilities of the polyanhydrides were found to be dependent upon the reaction conditions and the structure of the monomers used. The highest molecular weight ( M n = 12400) was obtained by thermal polycondensation of isolated acetic mixed anhydride prepolymers formed on the reaction of the diacids 3b, 3c , and 3i with acetic anhydride.