Poly(D,L-cactide/epsilon-caprolactone)/hydroxyapatite composites

In this study, elastomeric D,L-lactide and epsilon-caprolactone copolymers with two different molecular weights (M-n: 108.000 and 40.000) were synthes ized by ring-opening polymerization of the respective dimers by using stann ous octoate as the catalyst, as a potential bone-filling material. The fina l ratio of D,L-lactide to epsilon-caprolactone obtained by (NMR)-N-1 was 60 /40 (comparing to the initial ratio of 50/50). Both copolymers were amorpho us having T-g at around -21 degrees C. Different amounts of hydroxyapatite (HA) powder were loaded within the copolymers. These composites were easily shaped by hand. Mechanical properties of the composites changed with the H A loading and the molecular weight of the copolymer. The percent elongation decreased, while both the Young's modulus and yield point (stress) increas ed with the HA content. The copolymers were degraded within the Ringer solu tions in about 6 weeks. The molecular weight distribution became broader du ring degradation. Incorporation of HA reduced the degradation rate. (C) 200 0 Elsevier Science Ltd. All rights reserved.