Abstract
Polylactic acid (PLA) composite biomaterials were prepared by using biocompatible β-calcium metaphosphate (β-Ca(PO3)2) fibers. The composites showed bending strength of≈40 MPa and modulus of elasticity of 5 GPa similar to that of natural bone. The fracture of the composites proceeds step by step even beyond the maximum stress. After PLA and the composites were soaked in simulated body fluid at 37°C for 3 months, the strength of PLA was reduced seriously to≈1/5 as large as the initial value due to hydrolysis of PLA. On the other hand. degradation in the strength of the composites (e. g., fiber content of 35wt.%) was restricted to≈1/2 as large as the initial value. Although PLA was converted into a typical brittle material by the soaking, the composites in toughness were not degraded. The mechanical properties of PLA can be improved effectively by introducing the β-Ca(PO3)2, fibers.
