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

Poly (epsilon-caprolactone-co-alpha-iodo-epsilon-caprolactone) was synthesized by binding iodine to PCL chain bearing carbanionic site on alpha-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 (T(m), T(c), DeltaH(m)), 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.