TY - JOUR
T1 - Characterization of accelerated hydrolysis degradation of poly (lactic acid) in phosphate buffered saline solution
AU - Woo, Soo Hyun
AU - Wee, Jung Wook
N1 - Publisher Copyright:
© 2024 Elsevier Ltd
PY - 2024/5
Y1 - 2024/5
N2 - For the reliable use of polylactic acid (PLA) materials in the human body for supportive implants, an appropriate accelerated testing method to assess the lifetime of the PLA with an acceptable model that can describe the entire degradation process is required. In this study, accelerated degradation were conducted on the polylactic acid (PLA) exposed to the phosphate buffered saline (PBS) solution at elevated temperatures, 50 ℃, 60 ℃, and 70 ℃. The high level of accelerated degradation was achieved with elevating temperatures. The evolution of surface degradation degree with exposure time was quantified by measuring the molecular end group and modeled by a proper equation. In addition, it was demonstrated that hydrolysis-induced chain-scission is the governing mechanism in the accelerated degradation. The chemi-crystallization behavior with the hydrolysis degradation was also characterized. The morphological observation revealed that the microcracks and pits are pronouncing mechanisms of surface damage. The tensile properties were severely degraded after a certain period of induction time, depending on the temperature. The sorption kinetics were also assessed and explained during the entire lifetime until the severe mass loss, based on the diffusion with degradation behavior, as well as the evolution of the morphological damages. The formation of the surface degradation layer and subsequent damages are suspected to result in early saturation and secondary sorption behavior at the elevated temperature. Finally, the integrated correlations between the sorption behavior, amount of hydrolysis degradation, and mechanical property decrease were physically described, and accurate correspondences were obtained.
AB - For the reliable use of polylactic acid (PLA) materials in the human body for supportive implants, an appropriate accelerated testing method to assess the lifetime of the PLA with an acceptable model that can describe the entire degradation process is required. In this study, accelerated degradation were conducted on the polylactic acid (PLA) exposed to the phosphate buffered saline (PBS) solution at elevated temperatures, 50 ℃, 60 ℃, and 70 ℃. The high level of accelerated degradation was achieved with elevating temperatures. The evolution of surface degradation degree with exposure time was quantified by measuring the molecular end group and modeled by a proper equation. In addition, it was demonstrated that hydrolysis-induced chain-scission is the governing mechanism in the accelerated degradation. The chemi-crystallization behavior with the hydrolysis degradation was also characterized. The morphological observation revealed that the microcracks and pits are pronouncing mechanisms of surface damage. The tensile properties were severely degraded after a certain period of induction time, depending on the temperature. The sorption kinetics were also assessed and explained during the entire lifetime until the severe mass loss, based on the diffusion with degradation behavior, as well as the evolution of the morphological damages. The formation of the surface degradation layer and subsequent damages are suspected to result in early saturation and secondary sorption behavior at the elevated temperature. Finally, the integrated correlations between the sorption behavior, amount of hydrolysis degradation, and mechanical property decrease were physically described, and accurate correspondences were obtained.
KW - Accelerated testing
KW - Diffusion
KW - Hydrolysis
KW - Mechanical properties
KW - PBS
KW - PLA
UR - http://www.scopus.com/inward/record.url?scp=85186756361&partnerID=8YFLogxK
U2 - 10.1016/j.polymdegradstab.2024.110726
DO - 10.1016/j.polymdegradstab.2024.110726
M3 - Article
AN - SCOPUS:85186756361
SN - 0141-3910
VL - 223
JO - Polymer Degradation and Stability
JF - Polymer Degradation and Stability
M1 - 110726
ER -