抄録
In this study, immersion tests on poly (L-lactic acid) (PLLA)and their composite with β-tricalcium phosphate(β-TCP) to phosphate buffered solution(PBS) at 37℃ was carried out to investigate the effect of immersion in PBS on tensile mechanical properties. A simple phenomenological model to predict tensile elastic properties of hydrolyzed biodegradable polymer and their composites was also constructed by assuming voids generation in the hydrolyzed sites of the polymer. The analytical results for number averaged molecular weight are in good agreements with experimental results in any specimens, and it seems to be the evidence of autocatalytic hydrolysis of PLLA. Furthermore, the model shows that the hydrolytic degradation rate constant decreases with β-TCP contents. It means that β-TCP particle has inhibitive effect on hydrolytic degradation of PLLA. Although the predicted value has large error on the later scheme of hydrolysis, the model describes tensile elastic modulus trend of degraded PLLA and β-TCP/PLLA composites reasonably.
