Degradation and its theoretical evaluation of poly(lactic acid) under simulated body environment (Changes in molecular weight and crystallinity)

Abstract

The mechanical properties of bio-absorbable plastics, which is used as a bon fixation, change in the body because the plastics is hydrolyzed under the body environment. Theoretical prediction of the bio-degradation process will be useful for the medical application of these materials. Thus, a simple analytical model to predict hydrolytic characteristics of polymeric materials is necessary. In this study, several samples of poly(lactic acid) with different initial molecular weights, crystallinity and sample sizes were immersed in a phosphate buffered solution and the changes in the molecular weight and crystallinity were investigated. Theoretical analyses on the variation of these properties were performed and the results were compared with the experimental data. It is clarified that the theoretical results have successfully predicted the bio-degradation process of poly(lactic acid).

Keywords

• poly(lactic acid)
• bioabsorbable polymers
• molecular weight
• crystallinity
• young’s modulus