The evolution of the structure and mechanical properties of fully bioresorbable polymer-glass composites during degradation

Authors
Zhang, XC 
Best, SM 
Cameron, RE 

Loading...
Thumbnail Image
Type
Article
Change log
Abstract

Fully bioresorbable polymer matrix composites have long been considered as potential orthopaedic implant materials, however their combination of mechanical strength, stiffness, ductility and bioresorbability is also attractive for cardiac stent applications. This work investigated reinforcement of polylactide-based polymers with phosphate glasses, addressing key drawbacks of current polymer stents, and examined the often-neglected evolution of structure and mechanical properties during degradation. Incorporation of 15–30wt.% phosphate glass led to modulus increases of up to 80% under simulated body conditions, and 15wt.% glass composites retained comparable ductility to pure polymers, crucial for stent applications where ductility and stiffness are required. Two-stage degradation was observed, dominated by interfacial water absorption and glass dissolution. Polymer embrittlement mechanisms (crystallisation, enthalpy relaxation) were suppressed by glass addition, allowing composites to achieve a more controlled loss of mechanical properties during degradation, which could allow gradual transfer of loading to newly healed tissue. These results provide a valuable new system for understanding the structural and mechanical changes occurring during degradation of fully bioresorbable polymer matrix composites, providing important new data to underpin the design of effective cardiac stent materials.

Publication Date
2022
Online Publication Date
2021-12-08
Acceptance Date
2021-12-01
Keywords
Particle-reinforced composites, Polymer-matrix composites, Glasses, Environmental degradation, Mechanical properties
Journal Title
Composites Science and Technology
Journal ISSN
0266-3538
1879-1050
Volume Title
Publisher
Elsevier BV
Sponsorship
The authors thank Lucideon Ltd. for providing materials and financial support
Relationships
Is supplemented by: