Biodegradable bio-based polyesters with controllable photo-crosslinkability, thermal and hydrolytic stability

Biodegradable poly{3,4-dihydroxycinnamic acid (DHCA, coffeic acid)-co-lithocholic acid (LCA)} polyester was synthesized by polycondensation of DHCA and LCA. The molecular structure of poly(DHCA-co-LCA) copolymers was characterized by FT-IR and H-1-NMR measurement. The photo-crosslinkability of poly(DHCA-co-LCA) depended on their compositions and could be tuned by varying the monomer ratio. The presence of LCA in the copolymers enhanced the solubility and thermal stability. In addition, poly(DHCA-co-LCA) and PDHCA exhibited higher fluorescence emission intensity than DHCA monomer. Accelerated hydrolysis experiments revealed that the degradation rate of poly(DHCA-co-LCA) was slower than that of PDHCA.