Effect of β-tricalcium phosphate addition on the in vitro degradation of self-reinforced poly-l,d-lactide

The composite containing 20 wt% of osteoconductive β-tricalcium phosphate and 80 wt% of bioabsorbable poly-l,d-lactide (ll/dd dimer ratio 96/4) was manufactured using twin-screw extruder and self-reinforcing technique. The self-reinforcing created the porous surface and increased the mechanical properties of the composites. The in vitro degradation behavior of the self-reinforced composite was investigated comparatively with plain self-reinforced matrix polymer. The samples studied were characterized determining the changes in mechanical properties, thermal properties, molecular weight, mass loss and water absorption in phosphate buffered saline at 37 °C for up to 104 weeks. The results showed that the presence of the β-tricalcium phosphate modified the degradation of the matrix polymer. The degradation rate of the self-reinforced composites was slower than the degradation rate of the self-reinforced matrix polymer.