Synthesis of an X-ray opaque biodegradable copolyester by chemical modification of poly (ε-caprolactone)

Poly (ε-caprolactone-co-α-iodo-ε-caprolactone) was synthesized by binding iodine to PCL chain bearing carbanionic site on α-position of carbonyl groups using lithium diisopropylamide. Copolyesters containing from 10% to 25% of iodo-units were thus obtained. Viscoelastic properties (modulus, loss angle), thermal properties (Tm, Tc, ΔHm), crystallinity and in vitro degradability of this new type of copolymers were measured. Their opacity to X-rays was assessed, and appeared high enough to be of interest for biomedical applications.