Synthesis, characterization and in vitro degradation of poly(ester-anhydride)s based on succinic acid and 1,6-bis-p-carboxyphenoxyhexane

This paper describes synthesis and characteristics of functional poly(ester-anhydride)s bearing allyl pendant groups. The polymers were obtained by polycondensation of 1,6-bis-p-carboxyphenoxyhexane (CPH) and oligo(3-allyloxy-1,2-propylene succinate) terminated with carboxyl groups (OSAGE). The carboxyl groups in OSAGE and in CPH were converted to mixed anhydride groups by acetylation with acetic anhydride. After that, prepolymers thus obtained were condensed in vacuum to yield poly(ester-anhydride)s. The structure of copolymers was confirmed by NMR spectroscopy. Influence of molecular weight of OSAGE as well as of the CPH and OSAGE content on selected properties of poly(ester-anhydride)s was examined. Poly(ester-anhydride)s were subjected to hydrolytic degradation at 37 °C, in aqueous phosphate buffer solution of pH 7.41 (PBS). The course of degradation was monitored by determination of weight loss of samples and 1H NMR. Fracture surfaces of samples during degradation were examined by scanning electron microscopy.