Influence of dynamic compressive loading on the in vitro degradation behavior of pure PLA and Mg/PLA composite

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

13 Scopus Citations
View graph of relations

Author(s)

  • Xuan Li
  • Chenxi Qi
  • Linyuan Han
  • Chenglin Chu
  • Jing Bai
  • Chao Guo
  • Feng Xue
  • Baolong Shen

Detail(s)

Original languageEnglish
Pages (from-to)269-278
Journal / PublicationActa Biomaterialia
Volume64
Online published4 Aug 2017
Publication statusPublished - Dec 2017

Abstract

The effects of dynamic compressive loading on the in vitro degradation behavior of pure poly-lactic acid (PLA) and PLA-based composite unidirectionally reinforced with micro-arc oxidized magnesium alloy wires (Mg/PLA) are investigated. Dynamic compressive loading is shown to accelerate degradation of pure PLA and Mg/PLA. As the applied stress is increased from 0.1 MPa to 0.9 MPa or frequency from 0.5 Hz to 2.5 Hz, the overall degradation rate goes up. After immersion for 21 days at 0.9 MPa and 2.5 Hz, the bending strength retention of the composite and pure PLA is 60.1% and 50%, respectively. Dynamic loading enhances diffusion of small acidic molecules resulting in significant pH decrease in the immersion solution. The synergistic reaction between magnesium alloy wires and PLA in the composite is further clarified by electrochemical tests. The degradation behavior of the pure PLA and PLA matrix in the composite under dynamic conditions obey the first order degradation kinetics and a numerical model is postulated to elucidate the relationship of the bending strength, stress, frequency, and immersion time under dynamic conditions.

Statement of significance
We systematically study the influence of dynamic loading on the degradation behavior of pure PLA and Mg/PLA. Dynamic compressive loading is shown to accelerate degradation of pure PLA and Mg/PLA. The synergistic reaction between magnesium alloy wires and PLA in the composite is firstly clarified by electrochemical tests. The degradation behavior of the pure PLA and PLA matrix in the composite under dynamic conditions obey the first order degradation kinetics. Then, a numerical model is postulated to elucidate the relationship of the bending strength, stress, frequency, and immersion time under dynamic conditions.

Research Area(s)

  • Degradation kinetics, Dynamic compressive loading, Internal fixation implants, Load frequency, Mg/PLA

Citation Format(s)

Influence of dynamic compressive loading on the in vitro degradation behavior of pure PLA and Mg/PLA composite. / Li, Xuan; Qi, Chenxi; Han, Linyuan; Chu, Chenglin; Bai, Jing; Guo, Chao; Xue, Feng; Shen, Baolong; Chu, Paul K.

In: Acta Biomaterialia, Vol. 64, 12.2017, p. 269-278.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review